Barty emerges as Serena threat

ASHLEIGH Barty’s killer serve has emerged as the greatest second-week danger to Serena Williams’s quest for a seventh US Open crown and recordequalling 24th grand-slam title.

Barty’s through to the last 16 of a major for the first time — but isn’t done yet.

The 22-year-old former Wimbledon girls’ champion will carry a 2-1 winning record into her fourth-round clash with eighth-seeded 2016 Open runner-up Karolina Pliskova.

“Obviously Karolina’s played well here in New York before. She probably had her first biggest breakthrough here, when she made the final,” Barty said. “She’s got a very big game, a very big game.”

But Barty’s own big game was good enough to see off Pliskova in their only previous meeting on a hard court, in Wuhan last October. And now Australia’s 18th seed is bringing it in New York.

Statistics show Barty’s serve to be the second-most effective in the draw behind only Williams. The Queenslander has faced just eight break points in three matches, two more than Williams.

“The whole summer I’ve felt like I’ve served pretty well and I get myself ahead in service games and it’s always a good thing,” Barty said. “So when I can hit my spots on serves and try and dominate with my forehand as best as I can, I feel like I can control most of my service games.”

Keeping points short is also proving key to her progression through the draw.