He had his best Grand Slam performance at the 1974 French Open, where he reached the third round of the singles draw and was a quarter-finalist in the men's doubles, with Kenichi Hirai.[3] The same player partnered Sakai in the Düsseldorf Grand Prix tournament that year and the pair finished as runners-up.[3] Sakai and Hirai also won the men's doubles gold medal at the 1974 Asian Games in Tehran. It was Sakai's second gold medal of the tournament, having also won a gold medal in the singles, beating Iranian local Taghi Akbari in the final.[4]
In 1975, Sakai made his final Davis Cup appearances for Japan and registered his 20th and final win, over Phil Dent.[2] He took part in a total of 19 ties during his career.[2]