Former world No.1 Maria Sharapova, now playing as a wild card, made her presence felt in her return to the US Open after she ousted No. 2 seed Simona Halep in the first round via a 6-4, 4-6, 6-3 win in two hours and 44 minutes. With the win, Sharapova extended her mastery over Halep by winning for the seventh time in as many matches. The Russian, playing in a major tournament for the first time since serving a 15-month ban for use of a banned substance, also extended her first-round Grand Slam win streak to 23 matches.

She also remained undefeated in her past 11 opening rounds in the US Open.

Sharapova shed tears during an on-court interview, saying “it’s all worth it. You sometimes wonder why you put in all the work. And this is exactly why." Sharapova will next face Timea Babos, who defeated Viktorija Golubic, 7-5, 5-7, 7-5. The loss ended Halep’s bid for her first Grand Slam title and denied her bid to clinch the No.1 ranking. Heading into the US Open, Halep was just five points behind No.1 Karolina Pliskova.

Krunic stunned No.7 Johanna Konta

In the other major upset of the opening round, unseeded Aleksandra Krunic of Serbia ousted No.7 Johanna Konta, 4-6, 6-3, 6-4, in their opening-round clash.

The loss ended Konta's bid for her first Grand Slam singles title and a chance to clinch the No.1 ranking. In other matches, 11th seed Dominika Cibulkova of Slovakia survived a tough challenge from Jana Cepelova en route to a three-set win while No. 3 Garbine Muguruza, No. 13 Petra Kvitova and No.9 Venus Williams hurdled their first-round assignments. Other winners were Sloane Stephens, Carolina Wozniacki, Caroline Garcia, Julia Goerges, Magdalena Rybarikova, Maria Sakkari and Sofia Kenin.

No.4 Alexander Zverev led winners on men’s side

On the men’s side, No.4 Alexander Zverev defeated Darian King of Barbados, 7-6 (9), 7-5, 6-4, but 13th seed Jack Sock was not as lucky, losing to Jordan Thompson of Australia in five sets.

Aside from Zverev, fifth seed Marin Cilic, No. 8 Jo-Wilfried Tsonga, No. 10 John Isner and No. 12 seed Pablo Carreno Busta also advanced to the next round. Cilic had a shaky outing but held on to beat Tennys Sandgren, 6-4, 6-3, 3-6, 6-3; Isner prevailed over Pierre-Hugues Herbert, 6-1, 6-3, 4-6, 6-3; and Tsonga ousted Marius Copil, 6-3, 6-3, 6-4. Other winners were Cameron Norrie, David Ferrer, Sam Querrey, Gilles Muller, Steve Johnson, Lucas Pouille, Mischa Zverev, Kevin Anderson, Diego Schwartzman and Kyle Edmund.