The world number one started slowly in her first match since she clinched a fourth Grand Slam title at the US Open last month.
But the Belarusian found her power game in the final set to reach the Wuhan Open last 16, where she will face the 16th-seeded Russian Liudmila Samsonova.
Sabalenka is chasing a fourth consecutive crown in Wuhan where she has a perfect 18-0 win-loss record.
The first three games went against serve but it was Sramkova who consolidated for 3-1, and it was all she needed to grab the opening set in 35 minutes, firing 15 winners.
Sabalenka hit back to level and swept through the decider to win in just under two hours.
"She played incredible tennis, especially in the first set. There wasn't much I could do against her," said Sabalenka.
"I knew after that little break, it will be not that easy to get back in my rhythm.
"But I'm really glad that in the second set I found my game, I stepped in, and I think I played really great."
Gauff cruise
Third seed Coco Gauff, a semi-finalist in Wuhan last year, booked her place in the last 16 with a smooth 6-1, 6-0 performance against Japanese qualifier Moyuka Uchijima.
Gauff was flawless throughout a 51-minute victory that was her 18th on Chinese soil since 2023, the most at WTA level by any player in China during that period.
Gauff will square off with Chinese wildcard Zhang Shuai for a place in the quarter-finals.
In contrast, world number six Jessica Pegula survived a "wild ride", needing seven match points and almost three hours to overcome fellow American Hailey Baptiste 6-4, 4-6, 7-6 (8/6).
Pegula served for the win twice, at 5-2 and 5-4 in the third set, but Baptiste dug deep to save five match points and took four games in a row for a 6-5 advantage.
Pegula steadied the ship to force a tiebreak and she finally wrapped up the victory on her seventh match point.
"It's been brutal," said Pegula, who will face Russian ninth seed Ekaterina Alexandrova in the third round.
"Match points, then she started playing well, I think I just got a little tentative," admitted Pegula.
"And that's all it takes sometimes for someone to come back.
"I'm really proud of myself for how I held it together because I think I easily could have just collapsed. But I held tough, so yeah, that was a wild ride."
Heat again played a factor as 12th-seeded Karolina Muchova joined the likes of Emma Raducanu, Jelena Ostapenko and Dayana Yastremska on the list of mid-match retirees in Wuhan.
With temperatures soaring above 30C, Muchova struggled with the heat and had her vitals checked on court before she retired while trailing Magdalena Frech 7-6 (7/1), 4-1.