The two-time Wimbledon champion was ousted in the opening round of the Adelaide International warm-up event last week and looked to be heading for another defeat when he went a set down to the Chinese world number 97.
The Briton rallied to level up the contest, however, and raced away with the super tiebreaker to seal the win in just over an hour.
"He served well and was taking my time away but I managed to gradually improve as the match went on," Murray said, before explaining why he was still playing.
"I still love hitting tennis balls, I'm fortunate I'm able to do it at a high level, it's not the level that it was five or six years ago but ... I love the sport."
Current British number one Cameron Norrie (27) had a less straightforward day at the Auckland Open, needing nearly six hours to reach the quarter-finals with a 6-4 6-7(4) 6-3 win over Jiri Lehecka.
Much of that time was spent in the dressing room waiting for the wet weather to pass and the match was concluded indoors when the rain persisted.
Play had returned to the outside courts at the Auckland Open on Wednesday after being moved indoors with no crowds on Tuesday because of Cyclone Hale.
"It's tough on the concentration," said the world number 12, who remained unbeaten in the new season after three wins at the United Cup last week, including a victory over Rafa Nadal.
The rain was not the only problem Norrie faced and he had to dig deep to subdue the Czech after the 21-year-old had played sublime tennis to win the second set on a tiebreak.
"Credit to him, he really took it to me," said Norrie, who was raised in Auckland.
"I really enjoyed the time on centre court, it's good to be back in New Zealand, I'm just a little bit disappointed I couldn't talk in front of (the crowd)."
The opening second round match on the main showcourt had lasted only one set before Argentine Diego Schwartzman, who was trailing 6-1 to American Jenson Brooksby, withdrew with a leg injury.
Top seed Casper Ruud of Norway was knocked out following a 3-6 6-3 7-6(3) defeat by Laslo Djere in the evening session.
Djere was dominant from the baseline and brilliant with his serve before he came on top in the third set tie-break to record his first victory against a top-five player.
"I definitely fought hard for this one, coming back from one set down and winning the tie break. I am a bit exhausted, but also very happy," said the Serbian.
Former US Open champion Dominic Thiem also got his first win at Kooyong, beating American world number 17 Francis Tiafoe 7-6(4) 6-2.
The Austrian, on the comeback trail after a serious wrist injury, said that while he was not back at his best, the win showed he was "going in the right direction".
In the other ATP warm-up tournament in Adelaide, top seed Andrey Rublev crashed out in the second round of the Adelaide International 2 after losing 6-4 3-6 6-3 to local defending champion Thanasi Kokkinakis on Wednesday.
Cheered on by the home support, Kokkinakis wrapped up the match in just under two hours, hitting 35 winners and sending down 17 aces.
World number six Rublev struggled to find his form against Kokkinakis, who served incredibly well.
"He (Rublev) is a hell of a player," Kokkinakis said in his on-court interview.
"I am stoked I got one of my biggest wins in front of you guys (the crowd). That's awesome."