World number one Lee Chong Wei and Olympic champion Lin Dan moved closer to a dream world championship final as they reached the last eight in contrasting styles on Thursday. Lee was supremely brilliant during a 21-11, 21-5 victory over Park Sung-Hwan, the ninth-seeded Korean, getting so completely on top that the Malaysian was able to rehearse his entire range of tactical options. Lin though had to graft to win 21-16, 21-13 against Lee Hyun-Il, the 12th seeded Korean, starting slowly and trailing for two-thirds of the first game. The Chinese player, who is capable of the most explosive attack, was often obliged to dig deep in defence, at other times lifting and clearing patiently during lengthy rallies. These two faced each other in the 2008 Olympic final and two more wins for each would give the tournament the perfect climax on Sunday. "These are my seventh world championships and every time there are many more players from different countries who are difficult to beat," commented Lin. "Today I tried my best. He was mentally very well prepared and I am glad to have won." Lin began get on top psychologically during his advance from 14-14 to 20-15 in the first game, after which he moved steadily to a 11-5 lead in the second. The urgency of the rallies may have been a throwback to the notorious 2008 Korean Open final which Lee won after much aggravation over line decisions and harsh words from both camps. Lin denied though that any negative emotions remained. Meanwhile Lee's runaway success against Park came against the player who had ended Lin's world title defence in Paris last year. It was only a contest up to 9-6 in the first game, during which Lee used his easy, gliding movement and deep, accurate placements to create cumulative pressure. After that he opened up, risking full-on smashes and sliced overhead attacks early in the rallies, and discovering that he could often force his way through more quickly. Lee was then mixed it up, sometimes counter-attacking and switching between tactics. Afterwards seemed tense and nervous, perhaps concerned that he might have been peaking too soon or perhaps concerned giving away tactical secrets to opponents. "You already know what I was doing," Lee retorted when asked to comment on the wide range of options he displayed. "I don't want to comment on that, or on anything any more." Later Pi Hongyan's rehabilitation as a high level player continued, the China-raised former world number two from France reaching the quarter-finals as she had before a delighted crowd in the Stade Pierre de Coubertin last year. After a tight first game Pi's rhythm and confidence improved, and her resulting 21-18, 21-14 victory over Sayako Sato, the 16^th -seeded Japanese, was her second success against a seeded opponent in two days. She next faces Wang Yihan, the second-seeded former All-England Open champion from China, who came back from a game down to beat Inthanon Ratchanok, the rising 11th seeded Thai. There was also further progress for Kevin Cordon, the first Guatemalan ever to reach the quarter-finals, who beat his sparring partner Pablo Abian of Spain 21-19, 19-21, 21-17 and now faces Lee Chong Wei. Later however two Chinese seeds went out. Du Pengyu, the eighth seed, held a match point at 20-19 in the second game against Sho Sasaki, only for the battling Japanese player to earn a 10-21, 24-22, 21-10 triumph and a meeting with Lin Dan. Then Jiang Yanjiao, the fourth seed in the women's singles, was beaten 21-14, 7-21, 21-17 by Juliane Schenk of Germany, who now has a repeat of the European final against Tine Baun, the former world number one from Denmark.