Updated 9:56am: Croatian Marin Cilic has breezed into the semi finals of the US Tennis Open, with a straight sets win over sixth seed Tomas Berdych.

Cilic has won the quarterfinal 6-2, 6-4, 7-6, in just over two hours.

The 14th seed says he's really hitting his straps.

"Truly amazing day for me in very difficult conditions, very gusty.

"I think I adjusted a bit better than Tomas and I think what helped me was to get that lead a the beginning of the match and I was serving really well."

Cilic will meet either Roger Federer or Gael Monfils in the semis, with the pair meeting in this afternoon's last quarterfinal.