DEFENDING champion Naomi Osaka overcame a nervous start to scrape past Russian 20-year-old Anna Blinkova 6-4, 6-7 (5-7) 6-2 in the US Open first round.

Wimbledon champion Simona Halep was also taken to a third set by American Nicole Gibbs but won 6-3, 3-6, 6-2.

Osaka was 4-1 down in the opening set before she won five games in a row to take the lead.

In a second set riddled with errors, she saw off three set points and held match point before losing a tie-break.

The Japanese world number one, who made 50 unforced errors in the match, fought off three more break points in the decider.

She will now face Polish world number 53 Magda Linette in round two.

Romanian Halep took a fairly comfortable first set against Gibbs, ranked 135th, but despite holding off six set points, was broken for a fourth time late in the second.

But she cruised through the decider, breaking twice to ensure she avoided three successive first-round defeats in New York.

The fourth seed will face world number 116 Taylor Townsend, another American, in the second round.

There was, however, a first-round exit for two-time Grand Slam champion Garbine Muguruza, who lost 2-6, 6-1, 6-3 to Alison Riske.

American Riske, ranked 11 places below the Spaniard at 36th, sealed her first win at Flushing Meadows since 2013 and will take on former French Open champion Jelena Ostapenko in the second round.

 MUGURUZA OUT BUT KVITOVA THROUGH

“I remember not even that long ago, it was different. You had a difference between the top players and not top players,” said Muguruza, who has suffered three first-round defeats in New York.

“Now, you feel like if you’re not 100% every day you play, you know all your opponents can play great. It’s much more equal.”

Latvia’s Ostapenko overcame Serb Aleksandra Krunic 6-3, 7-6, (7-9), while two-time Wimbledon champion and sixth seed Petra Kvitova beat fellow Czech Denisa Allertova 6-2, 6-4.

Elsewhere, Swiss 13th seed Belinda Bencic won 6-3, 6-2 against Luxembourg’s Mandy Minella, while Dutch seventh seed Kiki Bertens defeated Spaniard Paula Badosa 6-4, 6-2.

And Canadian 15th seed Bianca Andreescu is through with a comfortable 6-2, 6-4 win over American 17-year-old Katie Volynets. (BBC Sport)