She was joined by Iga Swiatek, who reached her 25th WTA 1000 quarter-final with a hard-fought 7-6(2), 6-4 win over Belinda Bencic.
Sabalenka, in contrast to her rusty start against Rebecca Sramkova the day before, came out firing from the get-go to blow away Russia's world number 20 Liudmila Samsonova 6-3, 6-2 at the WTA 1000 tournament.
The match was played under a closed centre court roof on another hot day in China, where the start of play on outside courts was delayed to 2:30 pm from 11:00 am.
Sabalenka, whose unbeaten match run in Wuhan extended to 19-0 as she seeks a fourth straight title in the central Chinese city, took a month off after winning her fourth Grand Slam title at the US Open in early September.
She went on holiday to Greece, where she spent time hitting with former number one Djokovic, who is a resident there.
"I won a lot of points against him for the record," Sabalenka told reporters.
"I hope he's going to confirm that. We went for dinner. We practised a couple times.
"I hope I was a great hitting partner. So far, he's winning in Shanghai," she added.
"So I guess I was, it was a good one. I really hope he's going to go all the way.”
Sabalenka did not face a break point against Samsonova and was impressive on her second serve, dropping just three points from 16.
The Belarusian top seed wrapped up the win in 75 minutes and will face Elena Rybakina.
'Super hard'
Poland's Swiatek will face Italy's Jasmine Paolini for a place in the semi-finals
"I wanted to play with confidence and make great decisions because against Belinda, you can't let her dictate, so I really tried to do that," said Swiatek.
"It was super hard and every game was tough, that's why it was two sets and over two hours.
"But I'm happy I was there in the deciding moments, to be solid and to play one more shot back."
Bencic erased an early 3-0 deficit and served for the opening set at 5-4 before Swiatek halted the momentum and clinched it in a tiebreak after 72 minutes.
The second set was also a tug of war, but six-time Grand Slam champion Swiatek proved the steadier.
Rybakina, who is chasing a WTA Finals berth, knocked out last week's Beijing runner-up Linda Noskova 6-3, 6-4.
Seventh seed Paolini survived a barrage of winners from Denmark's Clara Tauson, who took the opening set before retiring with a right thigh injury when trailing 3-6, 6-1, 3-1.
"She was playing amazing tennis today and honestly, I was struggling a lot," said Paolini, who has now reached five WTA 1000 quarter-finals this season.
Paolini later withdrew from her doubles last-16 citing a gastrointestinal illness.
Jessica Pegula was made to battle through three sets for the second day running as she also reached the quarter-finals.
The American sixth seed, who had spent almost three hours on court against Hailey Baptiste on Wednesday, needed more than two hours to move past Russia's Ekaterina Alexandrova 7-5, 3-6, 6-3 and book a last-eight meeting with Czech qualifier Katerina Siniakova.