(Photo credit: Mike Frey-Imagn Images)

Coco Gauff fended off a feisty challenge from Leylah Fernandez as she continued her title defense Sunday at the China Open in Beijing.

Gauff defeated Fernandez, of Canada, 6-4, 4-6, 7-5 in a two-hour, 45-minute match, Gauff was forced to battle not only Fernandez but her old nemesis: her serve.

The No. 2 seed, Gauff hit four aces but added nine double faults. Fernandez was able to convert seven of her 10 opportunities into breaks, and Gauff won points on just 55 percent of her serves.

In her postmatch interview, Gauff acknowledged she didn't have a lot of breathing room.

'I did what I needed to do to win today,' the 21-year-old American said.

Fernandez, for her part, was broken eight times and converted only 49 percent of her serves into points.

Serving was the big issue in the third set, with nine service breaks. The biggest came with Fernandez serving at 5-5. She rallied back from love-40 to even the game at deuce, with Gauff going on to win.

'It was very physical,' Gauff said. 'We were going back and forth.'

In the next round, she will play No. 15 seed Belinda Bencic of Switzerland for a chance to advance to the quarterfinals.

Bencic rallied to defeat qualifier Priscilla Hon of Australia 4-6, 6-4, 6-3.

The No. 6 seed, Jasmine Paolini of Italy, defeated No. 27 seed Sofia Kenin for the first time in four meetings, advancing with a 6-3, 6-0 win. It was a dominant showing by Paolini, who won 61 of the 101 total points.

Waiting for Paolini is Czech Marie Bouzkova, a 6-3, 7-5 winner over Russia's Veronika Kudermetova, the No. 24 seed.

No. 3 seed Amanda Anisimova grabbed her 150th WTA match win with her 7-6 (11), 6-0 defeat of China's Shuai Zhang. Her next opponent will be the No. 15 seed, Czech Karolina Muchova, who advanced in a walkover against Paula Badosa of Spain.

The upset of the day came when Germany's Eva Lys, ranked No. 10 in the world, defeated former Wimbledon champion Elena Rybakina 6-3, 1-6, 6-4.

'I was trying to get a top 10 win the whole year,' said Lys, ranked No. 66.

'This is my first one. I'm very happy I finally got it done.'

Her next opponent will be McCartney Kessler, who moved on in a walkover against another former Grand Slam champ, Czech Barbora Krejcikova.

--Field Level Media