Andy Murray revelled in "one of the best wins" of his career after ending his long wait for a singles victory on the ATP Tour in gutsy fashion at the Zhuhai Championships on Tuesday night.

A tad fatigued but crucially feeling no pain in the right hip that has precipitated his fall from first to 413th in the world rankings, Murray dug deep into his replenishing resources to eke out a 6-3, 6-7(6), 6-1 victory over American world No 69 Tennys Sandgren at Hengqin Tennis Center.

The three-time Grand Slam champion had lost in two sets to Sandgren in the second singles match of his comeback at last month's Winston-Salem Open, so Tuesday's triumph demonstrated the Scot has since made significant progress in his recovery.

"I think in some ways it's one of the best wins that I've had, not in terms of just getting through that today, but everything that's gone into sort of getting back to this point," Murray said of the victory, which took 2 hours and 42 minutes in typically humid conditions in Guangdong province.

It was Murray's first win on the tour since he overcame Australia's James Duckworth in Brisbane on Jan 1 while battling a hip injury that prompted him to undergo a career-risking resurfacing operation on Jan 28 in London.

"You don't necessarily appreciate what it's like to be healthy at the beginning of your career. It's something that you take for granted and it's quite easy," said the 32-year-old, who will take on world No 31 Alex de Minaur on Thursday for a spot in his first quarterfinal since last year in Shenzhen.

Seventh seed di Minaur defeated fellow Australian John Millman 6-1,6-3.

"Obviously after the operation in January it's been difficult and it was undecided at times about whether I wanted to keep going or not," said Murray.

"But I'm really glad I got the win today and hopefully I'll be able to keep going."

Murray was particularly pleased with his movement and stamina in winning a number of long, taxing rallies against Sandgren.

"I'm tired and fatigued, but in terms of my hip, it feels really good. That's very positive and I'm very satisfied because in January I couldn't remember what it was like to play tennis and not have the pain in my hip. So now it's just pretty cool that I'm able to play without any pain there," said Murray.

Aside from his mobility, Murray's other major weapon, his serve, looked in good working order, with the two-time Olympic champion firing 13 aces.

He did not face a single break point in the match and mustered some spectacular shots, including a deep defensive lob to win a point in the second set and a handful of neat winners at the net after chasing down drop shots.

His efforts elicited plenty of 'oohs' and 'aahs' from some 3,000 fans at the night session.

Having also signed up to play at next week's China Open in Beijing followed by the Shanghai Masters, a tournament he was won three times, Murray is keeping his expectations in check during his China swing.

"My goal is to try to get two to three matches a week in all of the tournaments while I'm here," he said.

"If I got nine matches during the three weeks I'm here, I would think that would be a really, really good trip."