World number six Tomas Berdych battled his way into the semi-finals of the Thailand Open Friday, slamming 20 aces in a hard-fought victory over Lu Yen-Hsun.
The top seed was made to sweat for his 7-6 (9/7), 6-4 win against his Taiwanese rival, who has lost all 10 of his career quarter-finals.
"Credit to the opponent," said the big-serving Czech, 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."
Top seed Berdych needed a string of aces to claim his victory in just over one and three-quarter hours, 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 2013 win.
He now faces world number 14 Gilles Simon, who overcame a back injury and jet lag to struggle past Dutchman Igor Sijsling.
The Frenchman, seeded fourth and winner of the Bangkok event in 2009, 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."
Simon claimed victory in just under two-and-a-half hours with his eighth ace of the match after saving a slew of break points from the attacking Sijsling.
He won the opening set in 54 minutes, prevailing in a battle of classy ground strokes between the two men.
Sijsling rallied to claim the second set and looked to be in control early in the third when Simon was forced to take his on-court treatment.
But Simon regained his composure with a break for 4-3 and took victory three games later on his second match point.
In the day's other quarter-final matches, French defending champion Richard Gasquet staged a 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.
"I think I played very well tonight. Mikhail was very strong and played very, so it is a great win for me," said Gasquet, who sits ninth in the race for a spot in the eight-man ATP World Championships in London in November.
"I will hopefully do the same tomorrow and go out there and play my game, and try my best."
The tie between the tournament's second and third seeds will be a re-match of their US Open fourth round meeting less than a month ago.
Gasquet edged Raonic in five sets in New York.