American Marcos Giron eased past Aussie John Millman 6-4 6-2 to advance to his first ATP Tour semi-final in Sofia.

Giron, whom made the quarter-finals in Winston Salem, Metz and Halle earlier this year, had to beat off three break points but won 80 per cent of first service.

Giron broke Millman in the seventh game to win the first set and then broke twice in the fifth and seventh games to win the second.

“It feels awesome. First of all, tough match to John. He is a force on the ATP Tour, so I am really happy to get the win,” Giron said.

“It feels great to be in the semifinals, but I don’t want to stop there. I want to keep going.”

Giron will meet Gael Monfils in the semi-finals. Monfils beat Gianluca Mager 6-2 6-2.