Bet against her now at your own risk.

Alison Riske, the obscure Pittsburgh native, has stormed the U.S. Open, moving into the third round with yesterday’s 6-4, 6-2 victory over Germany’s Mona Barthel, the No. 28 seed, on Court 13.

Last year, Riske lost in the first round of qualifiers at the Open and flew home. Entering 2013, she never had won a main-draw tour match other than on the grass at Birmingham, Great Britain. But she’s had a decent year, improving to 10-5 in 2013 after her two surprising Open wins, moving her ranking all the way up to 81 and climbing.

“I must have heard my name a hundred times today,’’ said the 22-yearold Riske, a Steelers and Sidney Crosby fan who turned down a tennis scholarship to Vanderbilt.

Riske has made the semifinals twice at the famed Wimbledon tuneup in Birmingham.

“I do love grass, for sure’’ said Riske, who isn’t flashy and had zero aces yesterday.

This is Riske’s first full-time year on the WTA tour.

“I’m definitely excited,’’ Riske said. “I’m not really in the clouds. I only won a couple of matches. Obviously, I came here to do more than that.’’