Zhang Shuai of China competes during the women's singles third round match against Angelique Kerber of Germany at China Open tennis tournament in Beijing, China, Oct. 4, 2018. Zhang Shuai won 2-1. (Xinhua/Liu Jinhai)

BEIJING, Oct. 3 (Xinhua) -- On a day where several top seeds fell to lower-ranked opposition, local hero Zhang Shuai delighted her home fans at the China Open here on Wednesday, defeating Hungary's Timea Babos 6-1, 6-2 to book a place in the third round.

In a dominant performance, Zhang started as she meant to go on, racing into an early 3-0 lead in front of a partisan crowd. Babos notably struggled on serve, conceding ten break points in the first set alone.

Zhang raced into a 5-1 lead as an increasingly frustrated Babos started resorting to desperate drop shots in order to disrupt the hometown favorite's rhythm.

In a tense service game, Zhang was able to hold serve and close out the set with a thunderous backhand winner after another poorly executed drop shot from Babos.

The second set began with Babos finding more consistency in her service game. However, her groundstrokes let her down this time, leading to Zhang breaking serve at 2-2.

The Chinese player would not look back, winning three consecutive games to the delight of the home crowd to book a third round tie with Germany's No. 3 seed Angelique Kerber, who won her second round match 7-6, 6-1 against Spain's Carla Suarez Navarro.

In the biggest shock in the men's game, Serbian qualifier Dusan Lajovic beat No. 3 seed Grigor Dimitrov 6-2, 2-6, 6-4. The Bulgarian's service game proved to be erratic, as he struck nine aces but also made nine double faults throughout the match.

It was a difficult afternoon for Dimitrov who struggled to find his rhythm and hit 13 unforced errors. Lajovic seized on his opponent's inconsistent shot selection and finally broke serve at 3-3.

Dimitrov came out the gate strong in the second set, holding serve before converting his first break point of the match.

The two players exchanged breaks of serve and the Bulgarian started to find his range from the baseline, striking eight more winners and cutting down on unforced errors as he began to take control.

Under pressure, Lajovic continued to make errors, notably missing an easy volley at set point to hand the Bulgarian the set.

However, all that momentum was lost at the beginning of the third set, when Lajovic managed to break Dimitrov's serve for the fourth time.

This proved to be a decisive moment in the match, as both players would hold serve until the Serbian fired off an ace at match point to send the world no. 8 crashing out of the tournament.

Lajovic now faces No. 5 seed Kyle Edmund, after the Briton saw off Italian qualifier Matteo Berrettini 7-5, 6-7, 7-5 in a grueling encounter that lasted nearly three hours.

No. 1 seed Juan Martin del Potro won his second round tie in straight sets, but was pushed all the way by Russia's Karen Khachanov on the way to a 6-4, 7-6 win.

Both players were notably strong on serve throughout the match, but del Potro's break in the very first game proved to be enough to seal the first set, having made Khachanov work with some powerful baseline forehands.

In a match characterized by lots of aggressive play from the back of the court, both players remained on serve in the second set until 5-5, when they curiously both lost successive service games, forcing a tiebreak in which del Potro ultimately prevailed 7-4.

"I think I played a very good match today," del Potro said afterwards. "Karen is a difficult opponent who has big potential to grow in the [ATP] ranking soon."

The Argentinian now faces a third round tie against Serbia's Filip Krajinovic, who bested Spanish wild card Feliciano Lopez 7-6, 6-3.

Women's no. 2 seed Caroline Wozniacki beat Petra Martic 7-5, 6-3 in a tense affair in the afternoon session.

The first set alone clocked in at more than 71 minutes, as both players dropped serve twice in what would turn out to be a grueling contest.

The set came to a climax at 6-5, with Martic having to serve to stay in the set. At 30-30 Martic approached the net only to see Wozniacki pass her with a brilliant cross-court backhand. The Croatian hit a backhand into the net on set point, dropping serve and in the process handing Wozniacki the first set.

Wozniacki stepped up a gear in the second set, dropping serve once, but also breaking her opponent's serve twice. The Dane started to find her range, and after upping her first serve percentage from 60 to 80 percent she was able to see off a tough opponent.

No. 9 seed Sloane Stephens suffered a surprise third round defeat to Slovakia's unseeded Dominika Cibulkova 4-6, 6-2, 6-3.

The Slovakian started well, racing into a 3-0 lead, but Stephens pulled the contest back to 3-3 and was able to break Cibulkova's serve once more on the way to sealing the first set.

Undaunted, the diminutive Slovakian took the game to Stephens, breaking the American's serve three times in the second set to force a decider.

The third set saw more of the same, as Cibulkova took a 4-0 lead which ultimately proved unassailable, knocking Stephens out and setting up a quarterfinal against Latvia's Anastasija Sevastova, who defeated Donna Vekic of Croatia 6-3, 6-2.

In the pick of the men's doubles action, the Croatian duo of Ivan Dodig and Nikola Mektic beat the Chinese pair of Hua Runhao and Zhang Zhizhen 6-3, 6-4.

Meanwhile, in the women's doubles, Wuhan Open winners Elise Mertens and Demi Schuurs continued their good form, beating Anastasia Pavluychenkova and Anastasija Sevastova 7-5, 6-2.