Carlos Alcaraz overwhelmed Tomas Machac at the Shanghai Masters

World number two Carlos Alcaraz suffered a shock straight-sets defeat to the outstanding Tomas Machac in the quarter-finals of the Shanghai Masters.

Machac, ranked 33rd in the world, won a hard-fought first set tiebreak before emerging victorious 7-6 (7-5), 7-5.

Alcaraz put pressure on his Czech opponent's serve in the first set but failed to get two break points before losing in the tiebreak after just over an hour.

Machac then broke the Spaniard in the third game of the second set, but Alcaraz came back to level the score at 3-3.

However, erratic play at 5-5 cost Alcaraz his serve before Machac kept his composure and served for the win.

“I played unbelievably,” Machac said. “I knew my level would be great because I'm playing the best I have at the moment.”

“I had to play at this level, otherwise it’s 6-2, 6-3 and you go home. I’m glad I managed to play like that for two sets.”

Machac will face world number one Jannik Sinner in the semi-finals, with the Italian defeating Daniil Medvedev 6-1, 6-4.

Sinner lost just two points as he took a 3-0 lead and won the first set within 25 minutes.

Medvedev appeared to be struggling physically – he was holding his right shoulder after breaking it in the sixth game and received treatment after the opening set.

He improved and made the game a battle, but – after serving to make it 40-0 in the fifth game of the second set – was broken again by Sinner, who conceded the game with a double fault.

Medevev had a medical timeout after the seventh game before Sinner cruised to a comfortable victory in an hour and 24 minutes.

“I’m very happy with how I handled this game,” said Sinner.

“It felt like he had a little shoulder pain, he couldn't hit the forehand as well as he wanted to.”

“It was a great game, a great fight and let’s see what I can do in the semi-final.”

Meanwhile, Frenchman Richard Gasquet has announced he will retire after next year's French Open.

“I think this is the best moment for me,” the 38-year-old, who reached the Wimbledon semi-finals twice, told L'Equipe.

“It’s the best tournament for that. It’s great, as French we have the chance to stop in such incredible places.”