Queen's 2017: Grigor Dimitrov and Marin Cilic through to Aegon Championships semi-finals

Dimitrov is a two-time Grand Slam semi-finalist having reached the last four at Wimbledon in 2014 and this year's Australian Open

Former champion Grigor Dimitrov needed three sets to overcome Daniil Medvedev and reach the Aegon Championships semi-finals at Queen's Club.

The Bulgarian sixth seed led 5-0 after Medvedev injured his shoulder in the warm-up and required treatment.

The 21-year-old Russian fought back but Dimitrov eventually won 6-3 3-6 6-3 after one hour and 45 minutes.

Dimitrov will play Spain's Feliciano Lopez in the last four, while 2012 winner Marin Cilic meets Gilles Muller.

Croatian fourth seed Cilic beat American Donald Young 6-4 7-5 to set up the semi-final against Luxembourg's Muller, who won 6-4 7-6 (7-5) against American Sam Querrey.

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Dimitrov holds off Medvedev fightback

It appeared unlikely that the third quarter-final would even start when Medvedev called for the trainer during the warm-up.

The youngster, ranked 60th in the world, hurt his shoulder during a practice serve and had treatment before deciding to play.

After the first five games went to Dimitrov, a close contest developed and the Russian had his chances at a break up in the decider, finishing with 14 aces.

"It was a very tricky match," said Dimitrov.

"It's never easy to play a guy you've never played before. He's a very talented player, he definitely surprised me.

"I wasn't playing good tennis overall but those are the matches that I'm happy to win. Hopefully I can produce some better tennis tomorrow."

Lopez, 35, needed almost two and a half hours to win 7-6 (7-5) 6-7 (1-7) 7-5 against Czech seventh seed Tomas Berdych.

The world number 32 saved two match points at 5-4 in the final set before taking Berdych's serve in the next game, after earning his first break points of the match, with a brilliant passing forehand that video technology showed was initially incorrectly called out.

Big servers to meet in semis

Cilic and Muller will meet after both men reached the semi-finals without dropping serve in the tournament.

Cilic, the 2014 US Open champion, has not faced a break point in dominating his opening three matches, winning 78 of 84 points behind his first serve.

"I'm playing really well this week," he said. "I'm feeling great on the court and again today another match without losing serve, so that's extremely good."

Muller is in the form of his life at the age of 34, the left-hander taking his winning run on grass to seven matches in a row.

He is at a career-high ranking of 26 in the world and has already won the first two ATP titles of his career in 2017.

"It's a great feeling when you get that many matches in a row," said Muller.

"It does happen too often in a year for me, so to get this many wins in a row gives me a big boost and a lot of confidence."