EASTBOURNE, Great Britain - Top seed Caroline Wozniacki weathered a topsy-turvy challenge from Nottingham champion Ashleigh Barty to move into the Nature Valley International semifinals for the sixth time in her career.

Playing through the blustery coastal winds, Wozniacki needed an hour and 19 minutes to edge past Barty 6-4, 6-3.

“It was tough, very difficult match in very difficult conditions,” Wozniacki said in her on-court interview. “Ash is a great player and we know each other very well… I practiced with Ash early this week so I knew that it was going to be very tough.

“The wind didn’t help, it was swirling out there. It was so difficult to feel where the ball was going to go... I did my best and tried to stay aggressive.”

Both players were dialed in from the start of their heated quarterfinal clash - there was not much between Barty and Wozniacki in the first set, as Barty mixed in her slices and changes of rhythm against Wozniacki’s solid attack game. The first nine games in a row went comfortably to the server - Barty dropped no more than one point in each of her four service games, while Wozniacki faced just one break point in the whole set.

But, with the players deadlocked on serve and Wozniacki ahead 5-4, the scoreboard pressure seemed to take its toll on Barty, who faltered in the last game. The Aussie sprayed uncharacteristic errors and ended on a double fault to hand Wozniacki the lone break for the set.

After playing inch-perfect tennis for most of the first set, the second set unfolded a bit more loosely, with Wozniacki and Barty trading breaks twice as they struggled for the momentum. The winds picked up and made the conditions difficult for both players, but it was Wozniacki who adapted first, reeling off the last four games in a row to dismiss Barty in straight sets.

Wozniacki struck eight winners and 20 unforced errors across two sets, with most of the errors coming in the rollercoaster second set. Her rock solid game put Barty under a lot of pressure, and Wozniacki was able to break the Aussie four times in six opportunities. Barty outpaced her opponent with 15 winners, but her efforts were undone by her unforced error count, which was almost double her winners at 29.

Up next Wozniacki will face the winner between No.4 seed Angelique Kerber or No.7 seed Daria Kasatkina as she seeks a spot back in the Eastbourne final.

“Both are great players and both are great competitors - the next match is going to be very tricky either way,” Wozniacki assessed.