MELBOURNE, Australia — Sloane Stephens’ woes since her winning her first Grand Slam title at the U.S. Open continued Monday with a first-round loss at the Australian Open.

And Venus Williams fared no better in the following match.

The 13th-seeded Stephens was serving for the match in the 10th game of the second set against Zhang Shuai of China but dropped her serve. She was outplayed in the tiebreaker and also in the third set, with Zhang winning, 2-6, 7-6 (2), 6-2.

Williams, who lost to her sister Serena in last year’s final, was beaten 6-3, 7-5 by Belinda Bencic of Switzerland. Serena Williams is not defending her title after giving birth to her first child in September.

It always shaped as a tough opener for Stephens, who hasn’t won a tour-level match since her triumph at the U.S. Open last year, She faced a player ranked No. 34, two spots off being seeded for the first major of the season.

Stephens didn’t play last year’s Australian Open because of a left foot injury that kept her out of action until Wimbledon. Since beating Madison Keys in the U.S. Open final, Stephens has lost eight matches.

“Sloane, she plays so well, won the U.S. Open – everyone knows – she’s a great player,” Zhang said. “I know how hard I’m working … coming to Australia I’m ready for every match, every player. That’s why I won.”

In Williams’ loss, the turning point came late in the first set when play was stopped to allow for the roof to be closed because of rain at Melbourne Park. After already saving five break points at 4-3, Bencic returned from an almost 30-minute suspension to win six consecutive points and take the first set.

Bencic broke Williams’ serve in the final game of the match, winning the last four points. She clinched it when Williams, who had slipped on the far side of the court, couldn’t get to a ball in the open corner.

Bencic warmed up for the tournament by combining with Roger Federer to win the Hopman Cup for Switzerland.

There were two first-time major winners last year, and both were in action on adjoining show courts.

The French Open champion, Jelena Ostapenko, made a positive start with a 6-1, 6-4 win over 37-year-old Francesca Schiavone. The age gap between the 20-year-old Ostapenko and the 2010 French Open winner Schiavone was the biggest of any in the first round.

Ostapenko saved two break points in the third game of the opening set and clinched the set with an ace. After an exchange of service breaks in the second, Ostapenko got the decisive break in the ninth game, then served out the match.

The seventh-seeded Ostapenko is playing her third Australian Open – she advanced to the third round last year. Schiavone was playing in the Australian Open main draw for the 17th time.

In other early first-round results, 12th-seeded Julia Goerges extended her winning streak to 15 matches with a 6-4, 6-4 win over Sofia Kenin, Alize Cornet beat Chinese wild-card entry Wang Xinyu 6-4, 6-2 and No. 19 Magdalena Rybarikova beat Taylor Townsend 6-0, 7-5.

Goerges, a 29-year-old German, ended the year with tournament wins at Moscow and Zhuhai, then began 2018 with a win over Caroline Wozniacki in the final of the ASB Classic at Auckland, New Zealand.