Top seed Rafael Nadal reached the semi-finals of the Artois Championships for the first time with a hard-fought win over big-serving Ivo Karlovic.

Neither player could break serve before Nadal took a final set tie-break to win 6-7 (5-7) 7-6 (7-5) 7-6 (7-4).

He will go on to face defending champion Andy Roddick, who had a walkover after Andy Murray withdrew earlier on Friday.