Murray overcame an early break of serve in the marathon first set to force a tiebreak that was dominated by the veteran three-time major champion from Scotland.

The American top seed Fritz broke again early in the second set, which was enough to seal the set and stretch the contest into a decider.

In the tight third set, Fritz took advantage of a sloppy service game from Murray to arrive on the doorstep of victory at 5-4.

But Murray was not done and threatened to level when he jumped ahead 0-40 in the next game.

Fritz, who crushed 17 aces, managed to serve his way out of trouble and hit a lovely lunging volley to set up match point, which he converted with a cross-court forehand winner.

The match showcased not only both players' raw power but also their versatility, with each deploying deft drop shots at critical times, often leading to entertaining rallies on a hot and humid day.

Play was halted at one point by climate change protesters who threw large tennis balls with flames printed on them onto the court and unfurled banners calling on tournament sponsors Mubadala and Citi to stop funding the fossil fuel industry.

Fritz then capped a four-hour and 20-minute workday with a stress-free straight sets win over the Australian Thompson under the lights.

He will face Tallon Griekspoor for a place in the final after the Dutchman overwhelmed American J.J. Wolf 7-5 6-4 in the afternoon session.

Hometown hero Frances Tiafoe was unable to manage two wins during his double shift on Friday.

He rifled a forehand passing shot on match point to dispatch 18-year-old qualifier Shang Juncheng 6-2 6-3 in their postponed round of 16 tie, before running into a buzzsaw in the form of Briton Dan Evans, who cruised to a 6-4 7-5 triumph.

In the semis, Evans will take on Bulgarian Grigor Dimitrov, who reached the semi-finals without hitting a ball after he was handed a walkover by Frenchman Ugo Humbert.