World No.1 Ashleigh Barty of Australia, extended her winning streak to six with a 6-1, 7-6(7) defeat of Vera Zvonareva of Russia in the first round of the US Open in one hour and 28 minutes.
Fresh off the Cincinnati title and seeking her second Grand Slam trophy of the year after Wimbledon, Barty was flawless against the 2010 finalist in the first set, but needed to battle hard and save one set point to eke out a win in the second.
Zvonareva, bidding for her fifth career win against a reigning world No.1 and first since beating Caroline Wozniacki at the 2011 WTA Finals, did not get going until the fag end of the first set. The Russian won just nine points through the first six games to fall behind 1-5, including only three on Barty's serve.
But Zvonareva forced Barty to save two break points before closing out the opener, and then forced the Wimbledon champion in tough baseline exchanges throughout the second. Competing hard, the 36-year-old twice battled back to level from a break down, and it took Barty's best tennis to get over the line in the tiebreak.
The world No.101 Zvonareva raised her first serve percentage from 65 to 81 per cent in the second set and won six out of eight points at the net. Having been almost unable to return the Barty serve in the first set, Zvonareva began to read its direction and decrease the number of cheap points for the Australian.
"Obviously a tough one against Vera straight up," Barty told wtatennis.com, after her win. "She's an experienced campaigner. She knows how to get herself into matches. I think all in all, adapting to conditions was a little bit slower than I probably would have liked [but] we're through. We have another chance to improve on that in the next round."
"I think when my back was against the wall late in that buster, I came up with some really good stuff. That's all we can ask is when your back is against the wall, you trust yourself, you go out there and pick your spots and hit them," added Barty.
Barty will be up against 18-year-old Clara Tauson of Denmark, who won a contest between former junior world No.1s over Clara Burel of France 7-5, 6-0 in one hour and 14 minutes.
Both youngsters have surged into the top-100 this year, with Tauson winning her first WTA trophy in Lyon in March as well as the Chicago 125 two weeks ago, and Burel reaching the Lausanne final in July. World No.78 Tauson has had the upper hand in her rivalry with Burel so far, winning all their previous encounters in juniors and on the ITF World Tour, and that remained the case here.
Seeded duo Karolina Pliskova of the Czech Republic and Maria Sakkari of Greece both navigated past talented teenagers with straight-sets wins to get their US Open campaigns off to positive starts.
No.4 Pliskova progressed past wildcard Caty McNally of the U S 6-3, 6-4 in one hour and 23 minutes to extend her winning streak in major first rounds to 21. No.17 Sakkari posted a near-identical scoreline, 6-4, 6-3 over Marta Kostyuk of Ukraine in one hour and 31 minutes.
Sakkari's win means that two Greek women have won matches at a Grand Slam for the first time in the Open Era, following compatriot Valentini Grammatikopoulou's defeat of Anna Blinkova of Russia on Day 1.