Top seed Roger Federer avenged his Athens 2004 humiliation with a convincing win over Tomas Berdych on Wednesday as he stayed on course for an Olympic final with Rafael Nadal.
Federer was broken in each set but came roaring back each time to end it 6-3, 7-6 (7/4) and erase memories of the second round shock by the Czech which left him in tears four years ago.
Im very happy with the way I played. I havent lost to him since the Olympic Games, Federer said.
Hes always dangerous -- you can see how hard he hits the ball.
Earlier, Nadal and Novak Djokovic ended Russian involvement in the mens singles with straight-sets wins to also reach the last eight.
Nadal saw off Igor Andreev 6-4, 6-2 while Djokovic beat 13th seed Mikhail Youzhny 7-6 (7/3), 6-3.
Im playing close to my best level. I beat a very tough player today, said the Spaniard.
My feeling is go on court and try to play my best tennis all the time.
Nadal will next meet Jurgen Melzer after the Austrian ended the giant-killing run of Taiwans Lu Yen-Hsun 6-2, 6-4.
Third-ranked Djokovic will play Frances Gael Monfils, who put out Argentine seventh seed David Nalbandian 6-4, 6-4, for the prize of meeting Nadal in the semis.
Athens bronze-medallist Fernando Gonzalez and Paul Henri-Mathieu of France set up a last-eight meeting with wins against Olivier Rochus and Nicolas Kiefer respectively.
Federer, who finished fourth in 2000, will face James Blake in the quarter-finals after the US number one beat Gilles Simon 6-4, 6-2.
Meanwhile, Chinas Li Na delighted home fans with a 4-6, 6-2, 6-0 victory over Estonias Kaia Kanepi. She will face 2000 singles and doubles champion Venus Williams in the quarter-finals.
I couldnt find my rhythm at first -- I was completely unfamiliar with her, Li said.
But finally I got my chance. I feel lucky to play on my home court and with so many Chinese fans behind me.
However, there was heartbreak for Wimbledon semi-finalist Zheng Jie, who went down 6-4, 6-3 to Russian sixth seed Dinara Safina.
Serena Williams overcame a one-set deficit and racquet-smashing fit to beat French teen Alize Cornet 3-6, 6-3, 6-4.
Williams will face Elena Dementieva in the last eight as she bids to add another medal to her 2000 doubles gold. Sybille Bammer will play Vera Zvonareva while Safina faces world number one Jelena Jankovic.
Federer and Berdych traded breaks in their first set before the Swiss again got ahead and served out the set with an ace.
He netted a backhand to go a break down in the second but hit back in game five and dominated the tie-break, finishing it off with another ace and a service winner.
Incoming number one Nadal broke Andreev at 3-3 and saved four break points when serving for the set with a series of unreturnable deliveries.
The setback clearly affected Andreev and Nadal broke twice before taking the match with another big serve, making it four in a row against the 25-year-old.
Nadal is bidding for his eighth title this year after his fourth French Open crown and first Wimbledon win boosted his career trophy total to 30.
He is playing his first Olympic singles tournament after appearing as a little-known doubles player four years ago in Athens.
Nadals half of the draw has been eased by the exit of world number six Andy Murray, who was shocked in round one by Taiwans Lu. Defending champion Nicolas Massu has also been eliminated.
Nadal, Federer and Djokovic are all bidding to become the first top-five mens singles gold-medallist.
Nadal replaces Federer in the top ranking on Monday after more than three years at number two.