World number one Lee Chong Wei again proved a master of adaptability and economy as he overcame both Wang Tzu Wei and the enduring discomfort of his knee injury to reach the quarter-finals of the All-England Open.
Lee defended economically, controlled most of the rallies at a pace which was comfortable, defended sensibly, and mixed up the patterns cleverly as he squeezed through 21-18, 21-18 against the world number 21 from Taiwan.
There was never much in it, but Lee always managed to keep a point or two ahead, and when the most important moments of the match came, towards the end of each game, he found something a little unexpected.
The troublesome knee which he damaged on a badminton mat four weeks ago in Kuala Lumpur still is not completely right, and it was notable that Lee did not say he had come to win the All-England title again. There were, he thought, about five possible winners.
"I just tried to forget my injury," he said, when asked what he had tried to do. A little later he appeared to comment that "I just focus on my condition," perhaps describing what determined his movement.
It hinted that he may have been in two minds, both about playing here, and about what to expect from his heavily bandaged left knee. He nevertheless hopes it will continue to improve as he goes along.
He was, he agreed, playing a little more comfortably than on Wednesday and would focus optimistically on his next task, a quarter-final with last year's All-England runner-up, Tian Houwei, the seventh-seeded Chinese player.
If Lee wins that, he may earn himself a repeat of the Olympic Games final against Chen Long, another Chinese player.
Chen, who has played only one tournament since his Rio triumph seven months ago, is still a slightly unknown quantity, but even with so little match practice he was a firm favourite to come through his second round match against Tanongsak Saenssomboonsuk of Thailand later.
Earlier another Olympic hero, Pusarla Sindhu, looked in great form, hitting some startling winners in a 21-12, 21-4 success against Dinar Ayustine, the world number 39 from Indonesia, and increasing the possibility of a women's singles quarter-final with Tai Tzu Ying, the top-seeded Taiwanese.
"That wouldn't be easy," said Sindhu, who is seeded sixth. "But getting an Olympic silver medal has given me much more confidence. Whoever I play now I feel I can do well."