Olympic champion Lin Dan earned his most significant world tour showdown in two-and-a-half years with a third successive straight games victory to ensure a meeting with world champion Chen Long in the semi-finals of the All-England Open.

The 31-year-old Chinese legend out manoeuvred Kento Momota, a 20-year-old hero of Japan’s Thomas Cup world team triumph, by 21-18, 21-19 in Birmingham on Friday.

He proved himself as both a tactical maestro, and as possessed of the greatest range of strokes in the game.

Lin was slightly behind during most of the first game against an opponent who tended to prosper when he was able to launched speedy attacks. After getting his nose in front at 18-17, however, Lin was increasingly able alter the character of the match.

“I found a way to win the points more easily,” he said. “I tried to control the game and prevent Momota from making further attacks. I was really happy with the way I was able to adjust.”

Lin did it by mixing pushes to the net with accurate flicks and lifts to the back corners, and after winning the first game gained an immediate benefit from the change on mood.

He took six points in a row and then went on to 9-2, moving fluently and playing his cat and mouse game masterfully. Lin did, he admitted, lose a little concentration at that stage, and Momota reduced the deficit to just one point near the end.

But Lin reached match point with a rare smash and closed it out when he forced Momota to lift the shuttle wide, ensuring the all-Chinese semi-final showdown. Very shortly afterwards the top-seeded Chinese player, Chen Long, won 21-11, 21-11 against Chou Tien Chen, the sixth-seeded Taiwanese.

Predictably Lin did not feel it wise to speculate on the nature of a match with a compatriot, commenting merely that “it’s a team mate again – and I’ll try my best.” He had beaten Xue Song, another team mate, in three surprisingly difficult games in the first round.

Earlier another Chinese player, Sun Yu, the unseeded 21-year-old from Dalian, scored her second shock win in two days to become a surprise semi-final survivor in the women’s singles.

The improving Sun beat Ratchanok Intanon, the 20-year-old former world champion from Thailand, coming from 11-14 down in the second game and from 7-12 down in the third. Sun then built a six-point lead after which Intanon collapsed and called a halt.

Her injury was mysteriously self-inflicted as she attempted a routine smash, during which she toppled and fell prostrate. Eventually she was declared to have cramp in a calf muscle, giving Sun victory by a score of 11-21, 21-19, 19-13 retired.

It was hard not to sense that the injury had been related to self-inflicted wounds of a different kind, as Intanon produced some spectacular misses when in favourable situations to win the match.

She should have reached 19-19 in the second game but when presented with a short clear she dumped a smash into the net. Intanon should then have reached 13-7 in the third game but missed another smash from even closer in, with Sun turning away to protect herself.

After that Intanon‘s game imploded, causing her to lose 11 points in a row. She won only one more point before collapsing, needing several minutes of on-court treatment while Sun shook hands and departed to the changing room.

The previous day Sun had outplayed the Olympic champion Li Xuerui, 21-13, 21-12, taking her win with a similar calm as that against Intanon. The top-seeded Chinese player was still working her way back to fitness after spending time away with injuries, but Sun’s focus throughout was impressive.

Sun now plays Saina Nehwal, the world number three from India, who scored the first win of her career over Wang Yihan, the former world champion from China, by 21-19, 21-6.

The other women’s semi-final will be between Carolina Marin, the world champion from Spain, who beat Sung Ji-Hyun, the fourth-seeded Korean, by 21-18, 22-20, and Tai Tzu Ting, the seventh seeded Taiwanese who ended the title defence of Wang Shixian, the second-seeded Chinese player, by 21-18, 9-21, 21-19.