Aussie John Millman upset No.3 seed Grigor Dimitrov at the Delray Beach Open on Friday, recording a 6-4, 6-4 win over the world No.26 to set up a semi-final showdown with Reilly Opelka.

Millman last progressed to the semifinals of Nur-Sultan, Kazakhstan, where he went on to claim a first ATP title.

The Australian took the advantage early in the first set with a break in the ninth game and then recovered from a dropped service break early in the second set to win the tie in 94 minutes.

“I weathered a few little storms there and managed to hold my nerve there at the end,” Millman said.

“He’s been a good player for so long. You have to come out here and you have to play good tennis.

“You have to take care of your service games and you have to play quality from the back of the court because he’s so good at transitioning.”