Grigor Dimitrov of Bulgaria advanced to the semi-finals of the Stockholm Open by beating Kevin Anderson of South Africa 7-6 (7-3) 5-7 6-2 on Friday.
In the semi-finals he will face Olympic silver medalist Juan Martin del Potro of Argentina, who withstood 12 aces to beat Croatian veteran Ivo Karlovic 6-3 6-4.
Fourth-seeded Alexander Zverev beat German countryman Tobias Kamke 6-3 7-6 (7-5) to set up a semi-final against sixth-seeded American Jack Sock.
Sock won 6-4 6-4 against Portugal’s Gastao Elias, who had beaten top-seeded Gael Monfils in the second round.