Taiwan’s Lu Yen-hsun was forced to quit during his Queen’s Club quarter-final against Marin Cilic as the strain of playing two matches in the space of a few hours took its toll.
Lu had clinched a shock 6-3, 2-6, 7-6 (7/5) victory over third seed Janko Tipsarevic earlier on Friday to reach the last eight at the pre-Wimbledon warmup event for the first time.
However, the Tipsarevic match had been carried over from the previous day because of rain, meaning the world No. 57 had to return to action only a couple of hours later to face Cilic and his body was unable to cope.
The 28-year-old was already trailing 6-4, 2-0 against sixth seed Cilic when he decided to withdraw with a leg injury.
Lu had landed an early blow in his first ATP quarter-final this year when he broke Cilic in the second game of the opening set.
However, that only sparked Cilic into life and the Croatian hit straight back, breaking in the next game and again in the fifth to move 3-2 ahead.
That was enough of an advantage for the big-serving Cilic to close out the first set and he was back on the attack with another break at the start of the second.
Lu was showing signs of discomfort as he moved now and he called for treatment at 2-0 down.
The trainer spent several minutes working on his groin area, but Lu still seemed unhappy and was soon on his feet to tell Cilic that he would have to withdraw.
With the top five seeds already eliminated, Cilic must fancy his chances of winning the tournament.
His semi-final opponent is 2010 Queen’s champion Sam Querrey, who defeated Croatia’s Ivan Dodig 7-5, 3-6, 6-3.
It will be Querrey’s first ATP semi-final since August 2010 when he won the Los Angeles title.
Earlier, Bulgarian youngster Grigor Dimitrov reached the last four as he won a rain-interrupted clash against South Africa’s Kevin Anderson.
Dimitrov, a former junior champion at Wimbledon and the US Open, is regarded as one of the rising stars of the ATP Tour and he underlined his credentials by coming from a set down to beat ninth seed Anderson 4-6, 6-4, 6-3.
The 21-year-old, who is making his Queen’s debut, is so lavishly talented he has occasionally drawn comparisons with Roger Federer, but he is only just beginning to deliver on that promise.
This was his first ATP quarter-final of the season and he seized the moment with a dynamic performance in between the showers that forced play to be halted twice.
With his father watching from the stands, it was an emotional victory for Dimitrov, who will play 2002 Wimbledon finalist David Nalbandian in the last four after the 10th seed defeated Belgium’s Xavier Malisse 4-6, 7-6 (7/2), 6-4.
That was Nalbandian’s second come-from-behind win of the day, following his rain-delayed 4-6, 7-5, 6-3 victory over France’s Edouard Roger-Vasselin.
“I got a couple of tears. It was a good moment. I always wanted to share this with the people that I love so I was glad because my father was there. I think it was a big moment for him,” Dimitrov said. “I thanked him, basically. That’s what I told him after the match. I think it was an awesome experience for us.”