Koki Watanabe Badminton
2026 Results, Match by Match

Swiss Open 2026

Super 300・Basel, Switzerland

🇨🇭He reached the quarter-finals. On 11 March he went through when H. S. Prannoy (IND) withdrew; on 12 March he beat Su Li-yang (TPE) 21-10, 21-17; and on 13 March he lost the quarter-final to compatriot Yushi Tanaka 14-21, 17-21. 🏆Watanabe had won this tournament in 2023, and Tanaka went on to take the 2026 title — our own Swiss Open 2027 page calls the quarter-final a meeting of two Swiss Open champions.
🆕Added on 20 September 2026: all three were already on that page as the 2026 results, while this page still said we had no page at all for January to April — our own site disagreed with itself. ⚠️The Nippon Badminton Association's day page for 12 March labels the second round "third round"; English Wikipedia and our tournament page call it the second round. The opponent, the score and the date agree across all three. Neither source publishes match times for this event, so none are given.

76th All Japan Corporate Team Championships

All Japan Corporate Team Championships・Fukaya, Saitama, Japan

🆕He played four singles rubbers for BIPROGY and won three. 🔴Two of the four were against players who have a page on this site. In the group stage he beat Minoru Koga (AC Nagano Parceiro) 15-13, 15-11, and in the semi-final on 20 June he beat Kento Momota (NTT East) 15-13, 15-9. The quarter-final was 15-7, 15-8 against Yota Uchino. 🔴In the final on 21 June he lost the first singles rubber 15-11, 11-15, 13-15 to Tonami Transportation's Riku Hatano; our tournament page writes it from Tonami's side as 11-15, 15-11, 15-13. Tonami took the tie 3-1, and BIPROGY were runners-up. ⚠️Only the final is our own primary record; the other three come from the official live-results site. Played to 15 points, best of three, with no match times published.

Daihatsu Japan Open

Super 750・Tokyo Metropolitan Gymnasium

His best week of 2026: five matches, four wins and a runner-up finish. He beat Lakshya SEN (IND) 21-16, 21-14 in the first round on 15 July, Nhat NGUYEN (IRL) 21-15, 21-19 in the second on 16 July, Anders ANTONSEN (DEN) 21-13, 21-17 in the quarter-finals on 17 July and compatriot Yushi Tanaka 19-21, 23-21, 21-19 in the semi-finals on 18 July. In the final on 19 July, he lost to Christo POPOV (FRA, 5th seed) 11-21, 19-21. Three of his four wins came in straight games.

China Open

Super 1000・Changzhou, China

This Super 1000 started two days after the Japan Open final. He lost in the first round (round of 32) to Panitchaphon TEERARATSAKUL (THA). Our tournament page records this match only as a straight-games defeat, 0-2 on games; we could not confirm the point scores, and we do not publish numbers we have not confirmed.

BWF World Championships 2026

World Championships・New Delhi, India

🔴He did not play here, a month after finishing runner-up at the Japan Open. Entry was decided by the ranking on the cut-off date of 28 April, and he missed out by one place and was first reserve. Japan's men's singles entries were Kodai Naraoka, Kenta Nishimoto and Yushi Tanaka. Christo POPOV, who had beaten him in the Japan Open final on 19 July, was seeded 5th here and drew Kenta Nishimoto in the first round.

China Masters

Super 750・Shenzhen, China

In the first round on 1 September he lost to Jason GUNAWAN (HKG) 12-21, 17-21 in 44 minutes. Two days later, on 3 September, Gunawan also beat the men's singles top seed Jonatan CHRISTIE (INA) — our record of that match reads 16-21, 16-21 from Christie's side. 🏆Gunawan went all the way, beating fellow Hong Kong player LEE Cheuk Yiu 21-9, 21-16 in the final on 6 September: the player who beat Watanabe in the first round won the tournament.

Asian Games 2026

Asian Games・Ichinomiya, Aichi, Japan

He was one of the ten men in Japan's squad (named on 19 May 2026) and, with Yushi Tanaka, entered for the team event only in men's singles (he was World No. 21 on the list used for that announcement, dated 5 May 2026). Japan's men (seeded 4th) beat Kazakhstan 3-0 in the first round on 21 September and lost 0-3 to India in the quarter-final on 22 September. Watanabe was one of the ten men registered for the team event, but we have not recorded his team matches.

S/J League 2026-27

Japan domestic league・BIPROGY, men's J block

Japan's top domestic league. The official S/J League beginner's guide lists him as one of four men's players to watch (as published on 29 August 2026). His club BIPROGY plays in the men's J block. The regular season runs from 31 October to 31 January, with the TOP4 Tournament on 20 and 21 February at Yokohama BUNTAI. Line-ups for each fixture are chosen by the clubs, so we do not guess at names.

80th All Japan Championships

All Japan Championships・Chofu, Tokyo

Japan's national championship. According to BIPROGY's official career summary, he was the men's singles runner-up in 2023 and third in 2024. The 80th edition runs from 24 to 30 December 2026 at Keio Arena TOKYO in Chofu. Kodai Naraoka won the 2025 title at the 79th edition. The draw is usually published one or two weeks before the event.

On 19 July 2026 Koki Watanabe stood in the final of the Daihatsu Japan Open (Super 750) at Tokyo Metropolitan Gymnasium, having won four matches to get there. A month later, when the 2026 BWF World Championships began on 17 August, he was not there. Entry was decided by the ranking on the cut-off date of 28 April, and he missed out by one place and was named first reserve. We held both of those facts as primary records — but on two separate tournament pages, so they could not be read side by side.

• 🏸15 July, first round: Lakshya SEN (IND) 21-16, 21-14. Sen was World No. 13 on 8 September 2026.
• 🏸16 July, second round: Nhat NGUYEN (IRL) 21-15, 21-19.
• 🔥17 July, quarter-final: Anders ANTONSEN (DEN) 21-13, 21-17. Antonsen was World No. 5 on 8 September 2026.
• 🇯🇵18 July, semi-final: compatriot Yushi Tanaka 19-21, 23-21, 21-19. His only three-game match of the week, with the second and third games both decided by two points.
• 🥈19 July, final: Christo POPOV (FRA, 5th seed) 11-21, 19-21. Popov was then seeded 5th at the World Championships Watanabe did not play.

🔁Antonsen had beaten him once before, in a final. BIPROGY's official career summary lists him as runner-up at the 2024 Denmark Open (Super 750) in October 2024, where Antonsen won the title; the ranking list dated 22 October 2024 then put Watanabe at his career high of World No. 11. Our tournament pages cover 2026 events only, so we do not publish a score for that 2024 final.

Every 2026 score above comes from our own tournament pages. World rankings are updated every week, so every ranking on this page is written with its date.

• 2026 — Daihatsu Japan Open — runner-up (Super 750)
  He lost the final 11-21, 19-21 to Christo Popov (FRA) on 19 July. In the quarter-finals Watanabe had beaten Anders Antonsen (DEN) 21-13, 21-17 in straight games.
• 2026 — Singapore Open — semi-finals
  He lost the semi-final to Loh Kean Yew (SGP) on 31 May. BIPROGY's official career summary lists it as a third place in 2026.
• 2026 — Asian Games — in Japan's squad, team event
  One of the ten men named on 19 May 2026. In men's singles he and Yushi Tanaka were entered for the team event only; Japan's men lost 0-3 to India in the quarter-final.
• 2024 — Canada Open — champion (BWF World Tour Super 500)
  Calgary in July. It was his first Super 500 title, beating Kodai Naraoka in the semi-finals and Alex Lanier (FRA) in the final.
• 2024 — Denmark Open — runner-up (BWF World Tour Super 750)
  Odense in October, his first Super 750 final, lost to Anders Antonsen. The ranking list dated 22 October 2024 put him at his career high of World No. 11.
• 2023 — Swiss Open — champion (BWF World Tour Super 300)
  Basel in March, beating Lee Zii Jia (MAS) in the semi-finals and Chou Tien Chen (TPE) in the final. 🆕At the same event in 2026 he reached the quarter-finals, where Yushi Tanaka beat him and went on to win the title.
• 2023 — All Japan Championships — men's singles runner-up
  According to BIPROGY's official career summary he was runner-up in 2023 and third in 2024. The 80th edition takes place in December 2026.
• 2019 — Orleans Masters — his first BWF World Tour title
  Orleans, France, in March. He also won the Osaka International that year.

At the 2026 Asian Games in Ichinomiya, Aichi (20 to 29 September), he was entered for the team event only in men's singles, along with Yushi Tanaka. Japan's men beat Kazakhstan 3-0 in the first round and lost 0-3 to India in the quarter-final (we have not recorded his team matches).

🗓️October in Europe: First, on the association's self-funded list, he reached the semi-finals of the Arctic Open 2026 (6–11 October, Finland, Super 500) as the eighth seed. He beat WANG Tzu Wei (TPE) 21-14, 21-18, Brian YANG (CAN) 21-17, 20-22, 21-15 (78 minutes) and the defending champion and third seed Chou Tien Chen (TPE) 21-19, 21-16, then lost the all-Japanese semi-final on 10 October to Yushi Tanaka 14-21, 21-11, 16-21 (63 minutes). ⚠️These four matches are not in the nine-match count up to 1 September (in the Keep your own scoresheet section below). After that, as part of the Japan squad the Nippon Badminton Association named on 11 September 2026, he played men's singles at the Denmark Open 2026 (13–18 October, Super 750) (he is in the same squad for the French Open 2026 (20–25 October, Super 750), where the main draw published on 15 October gives him LEONG Jun Hao (MAS) in the first round again, unseeded; withdrawals after the draw are still possible, so please check the BWF draw for the latest). In Denmark he beat LEONG Jun Hao (MAS) 21-6, 21-19 in the first round on 13 October, then lost to third seed Chou Tien Chen 19-21, 20-22 on 15 October and went out in the second round. ⚠️These two Denmark matches are not in that count either (scores from Watanabe's side).

After Europe the season turns domestic. S/J League 2026-27 starts on 31 October, and his club BIPROGY plays in the men's J block. Then comes the 80th All Japan Championships from 24 to 30 December — an event where he was runner-up in 2023 and third in 2024.

⚠️ Neither the S/J League line-ups nor the All Japan draw has been published. We do not guess at names. Linked pages are in Japanese unless marked EN.

Up to 1 September 2026 we hold nine matches for Watanabe from international events, score by score: five wins and four defeats. (The Arctic Open and Denmark Open matches after that are not in this count; they are in the What's next section above.) Four of the five wins came in straight games, and the only three-game match was his semi-final against Yushi Tanaka on 18 July — in that same tournament, all four of Tanaka's matches went to three games. Read the two player pages side by side and the same week looks like two different weeks. Two results sit outside those nine: his first round at the Swiss Open in March, where the opponent withdrew, and the All Japan Corporate Team Championships in June, a team event played to 15 points, where he went 3-1.

🔴A results table does not show who he beat. On the ranking list dated 8 September 2026, Anders Antonsen was World No. 5 and Lakshya Sen No. 12 — Watanabe himself was No. 17 on the same list. Neither name appears in a line that just reads "runner-up".

🏢Something else shows up only when our player pages are read side by side. Watanabe's club, BIPROGY, is also the club of women's doubles pair Rin Iwanaga and Kie Nakanishi. In S/J League 2026-27 BIPROGY plays in the men's J block and the women's S block — two different blocks in the same league.

Badsheet records your own matches point by point, builds an official-style scoresheet and charts win rate and shot placement.

📮 Corrections and removal. This is an unofficial summary built from published information. If anything here is factually wrong, or if the player or their team would like this page taken down, please contact us and we will correct or remove it promptly. We do not publish anything about injuries, health or private life.