British number one Katie Boulter stormed through to her first WTA 500 semi-final with a straight-set victory over Croatia's Donna Vekic at the San Diego Open.
Boulter overcame strong winds in California to wrap up a 6-4 6-3 win over the seventh seed.
The 27-year-old will play Daria Saville of Australia or American third seed Emma Navarro in the last four.
"It was an absolute battle in very tricky conditions," said Boulter.
"It was not easy to get any rhythm because we are both big hitters. I found it tough to get into the match and just tried to stay as strong as I could in the head.