Karlovic fires 29 aces to down Khachanov

Vienna - Big-serving Ivo Karlovic saved a match point and fired 29 aces to defeat Russia's Karen Khachanov 6-7 (5/7), 7-6 (7/5), 6-3 to reach the Vienna ATP semi-finals on Friday.

Karlovic, 17 years older than his 20-year-old opponent, saved the match point in the 12th game of the second set.

The Croatian veteran will next face sixth seed and 2011 champion Jo-Wilfried Tsonga of France who defeated Spain's Albert Ramos-Vinolas 6-2, 7-6 (7/5).

Karlovic has a season-leading 1,081 aces, ahead of John Isner's 1,046.

Isner later faces top seed Andy Murray who will be continuing his bid to unseat Novak Djokovic as world number one.

The winner of that match will face either defending champion and fifth seed David Ferrer or Serbia's Viktor Troicki.