NOTTINGHAM, Great Britain - Unseeded American Jennifer Brady upset No.4 seed Maria Sakkari to reach the semifinals of the Nature Valley Open, 7-5, 6-3, on Friday.

Behind eight aces and five breaks of serve, Brady scored her second win against Sakkari all-time to advance to her first semifinal in nearly two years. 

"I haven't played a point yet on grass...but there's nothing you can do. You can't control the weather. I'm really happy with the way that I competed today," Brady said.

"I had a bit of a slow start. She started very well. She was playing really aggressive, taking my serves early and cracking returns. She made me feel the pressure a bit, but I was happy with the way I hung in there and I was able to close it out on serve."

The American fell behind early, as she lost serve in the first game and surrendered her serve a second time to fall behind 4-1.

However, the World No.80 slowly worked her way into Sakkari's service games from there, and broke for the first time in a sixth game where the Greek had chances to extend her lead to 5-1.

Brady eventually won the last four games of the opener, as she held to love in the ninth game to force Sakkari to serve for the set, but nonetheless never needed to save set point.

The 24-year-old held to love to start the second set, and broke immediately after to take a lead she hardly relinquished from then on.

After Sakkari won a pair of games to draw level at 2-2, she was never able to wrestle the lead away from Brady, who won four of the last five games to seal a spot in the final four. 

In the semifinals, Brady will face top seed Caroline Garcia, who rallied to end the run of Romanian qualifier Elena Gabriela Ruse in three sets, 4-6, 7-6(3), 6-1.

The American has won all three of her matches against the Frenchwoman this year, all three of which came on hardcourts.

With the weather forecast looking up for Saturday in Nottingham, the pair might contest their first-ever match on grass in their sixth meeting all-time.

"I've played Garcia three times this year, so I guess you can say we're kind of familiar with how the other plays," Brady said. 

"If we play on grass, it's a different matchup, but I'm looking forward to playing in the semifinals."