San Francisco Frontiers - Sinner out of Shanghai Masters as Djokovic battles into last 16

The 38-year-old Serb battled through to the last 16 with a 4-6, 7-5, 6-3 win over qualifier Yannick Hanfmann, despite admitting that he had been "hanging by a rope" early in the match.

It was a sorry end for Sinner, who had been hoping this week to add to his China Open victory.

The world number two began to experience issues in the fourth game of the third set, trying doggedly to persevere before abandoning the match at 6-7 (3/7), 7-5, 3-2.

Sinner ended the fourth game crouched over in pain and limping around the court.

He tried to play through it but did not improve, hitting the ball into the net multiple times to provide an easy break for his opponent.

He could barely walk at the end of the fifth game and had to be helped to his chair before accepting reality and calling it quits.

"(It was) a very unfortunate ending to what I thought was a high-quality match," Griekspoor said.

"Not the way you want to win -- brutal conditions here... I wish him a speedy recovery."

After an evenly matched first set, four-time Grand Slam winner Sinner had shown his teeth in the tiebreak, hitting two aces to take an early lead.

In the second set the tension picked up, with Griekspoor surviving three break points in the second game.

But it was the Dutchman who broke in the 11th game with a backhand, pushing the match into post-midnight territory.

- Djokovic digs deep -

Earlier, 24-time Grand Slam winner Djokovic was given a mighty scare by the 150th-ranked Hanfmann.

The Serb fired two aces to start, delighting the crowd, but soon ran into trouble as Hanfmann found his range.

The German broke in the third game and held serve after that to clinch the first set.

"I was just outplayed by a better player for a set and a half –- I was hanging by a rope to stay in the match," Djokovic said.

Neither player was able to take control of a gruelling second set, until a series of unforced errors from Hanfmann in the 12th game gave Djokovic the opening he needed.

Sweating in 28C humidity at 9:00 pm, the 24-time Grand Slam champion then broke in the fourth game of the third set as his 33-year-old opponent's precision dropped.

Cheered on by a stadium full of adoring fans, Djokovic held his resolve to take the third set after Hanfmann hit the ball out.

"I had to dig in really, really deep to come out from this match as a winner, and I think the energy and support of the crowd really got me out," Djokovic said.

- Fritz out -

The United States' Taylor Fritz was another top-10 casualty of the day, after he fell to 37th-ranked Giovanni Mpetshi Perricard 6-4, 7-5.

On a hot afternoon, the world number four seemed lethargic and struggled to get into his stride, unnerved after Mpetshi Perricard nearly broke twice in the fifth game.

That preempted a streak of brilliance that saw the neon orange-clad Frenchman fire three aces to hold the sixth, then break in the seventh.

A closely fought second set came to a head in the 11th game when a double fault by Fritz handed Mpetshi Perricard the advantage, which he swiftly converted with a backhand.

Finishing the match off with two aces, the big-serving 22-year-old said he could be proud of himself.

"It was tough to be honest, tough conditions, very humid," he said.

"The game at 5-5 (in the second set), it was terrible. I thought I was dying on the court," he chuckled.

Mpetshi Perricard will next face 11th-ranked Dane Holger Rune, who beat France's Ugo Humbert, 6-4, 6-4.

U.Campbell--SFF