Chinese Zheng Saisai gave the home crowd at the 2019 China Open a National Day gift, as she stunned American Sloane Stephens in the round of 32, on Tuesday evening.

In straight sets, 6-3 and 6-1, it was Zheng's first career victory against Stephens after the Shaanxi native won her first WTA singles title at 2019 Silicon Valley Classics in August.

The opening set saw both players held to love in their initial service games, followed by the first break point scored by Zheng.

The two then served out to 3-all, where a long fight at deuce ensued that saw Zheng brought to break point five times.

Stephens went on to convert this chance, but it would be the only one she managed to get for the rest of the match. Zheng broke twice more and sealed the opening set.

Zheng stormed to a 5-1 lead in the second, helped along by Stephens coughing out a series of unforced errors from both sides. Despite a few scares when serving for the match that saw Stephens go two points up, Zheng managed to stitch things up with a series of spectacular cross-court shots off the forehand.

Zheng played well on both offensive and defensive fronts, saving seven of the eight break points she faced and converting five of the six she created.

"I served pretty good today for the first serve, the angles. I was serving okay today. Gave her little bit (of) pressure. Not like the last two matches, I didn't actually serve well," Zheng said.

Zheng must survive a match against world no. 1 Ashleigh Barty to reach the quarterfinals.

The Australian scored her first-ever win in Beijing to take out No. 37 Yulia Putinseva of Kazakhstan in straight sets, 6-4, 6-2.

Murray faced and won Berrettini 

On men's side, starting off the day on the Diamond court, former world No. 1 Andy Murray had his first match against a top-20 player since his hip surgery, needing two tie breaks to defeat 8th seeded (and world No. 13) Matteo Berrettini of Italy, 7-6 (2), 7-6 (7).

Murray played a very conservative game from the baseline, staying in rallies for the long haul and giving his opponent very little space on return.

The two players held each other's services to love to 2-all in the opening set, before the Italian drew first blood, breaking Murray's service with play from the baseline every bit as aggressive as Murray's was muted.

Murray went on to get a break of his own to level the set at 5-all, and the two served out the remainder to take it to the tiebreak, where Murray stormed to the 7-2 margin with ease, sealing the set in just under an hour.

The two players traded break points early in the second set before going on to serve out the rest of their games, requiring yet another tiebreak. Berrettini was put up more of a fight in the second go around, serving for the set twice but proving unable to convert and force a decider.

Berrettini's aggressive forehand was both his best asset and his undoing. He hit 36 winners (20 off the forehand side) but almost as many (37) unforced errors, with 20 unforced coming off that side as well.

Next, Murray will face qualifier Cameron Norrie, also from the UK, in the round of 16.

Top seed Dominic Thiem of Austria had a straightforward 6-4, 6-1 victory over Richard Gasquet of France, setting up a meeting with home player Zhang Zhizhen in the last 16.

(With input from Xinhua)