The top four seeds all booked their respective places in the semi-finals of the Thailand Open in Bangkok on Friday.
Big-serving Tomas Berdych led the way, slamming 20 aces in a hard-fought 7-6 (9-7) 6-4 victory over Lu Yen-Hsun.
The world No 6 was made to sweat for his straight sets win against his Taiwanese rival, who has lost all 10 of his career quarter-finals.
The Czech star needed a string of aces to claim his victory, coming back from a break down in the opening set. He only lost serve once while breaking his opponent three times.
Berdych last won a trophy in October in Stockholm and remains the only member of the ATP top 10 without a trophy this year.
"Credit to the opponent," said the 28-year-old, who was playing in Bangkok for the first time in half a decade.
"Sometimes I felt like I was in PlayStation. He was hitting so fast, so low and making so many winners. It was a tough match and I'm happy to go through. He played well. It proves how tough tennis is these days."
He now faces 2009 champion Gilles Simon, who overcame a back injury and jet lag to struggle past Dutchman Igor Sijsling.
The fourth seed called for the trainer after the opening game of the final set, but recovered to take the match 6-4 5-7 6-4.
"My back is not in a great shape now. The injury is a bit of everything," said Simon, who is bidding to reach his third Thailand final, having lost to compatriot Richard Gasquet last year.
"I'll just take treatment and hope to be fit for Saturday. I have to be 100 percent if I want to win."
Second seed Gasquet staged an excellent fightback to overcome Russian fifth seed Mikhail Youzhny 5-7 6-3 6-1 with six breaks of his opponent.
In the last four he will take on Canadian third seed Milos Raonic, who fired 19 aces in a 58 minute rout of Spain's Feliciano Lopez 6-4 6-3.