New York, Aug 30 : America's No.6 seed Coco Gauff got the better of fellow teenager Mirra Andreeva for the second time in a Grand Slam this year, winning 6-3, 6-2 in 75 minutes with a near-flawless performance to reach the third round of the US Open, here on Wednesday. The result puts Gauff into the third round at Flushing Meadows for the third time in five appearances, and for the third time in a major this year. The American, a champion in Cincinnati two weeks ago, extends her winning streak to seven matches, the third-longest at tour level of her career so far. The 19-year-old Gauff previously defeated 16-year-old Andreeva 6-7(5), 6-1, 6-1 in the third round of Roland Garros on the latter's Grand Slam debut. The pair are two of the four highest-ranked teenagers on the WTA rankings, with No.63-ranked Andreeva behind only Gauff and two Czech 18-year-olds, Linda Noskova and Linda Fruhvirtova -- the latter of whom she is guaranteed to overtake after the US Open. /IANS