Nadal battles back to book semi-final spot

Top seed Rafael Nadal had to battle from a set down against big-serving Croatian Ivo Karlovic to secure himself a semi-final date with Juan Martin del Potro at the BNP Paribas Open.

Karlovic, who missed much of last year through injury, clinched the opening break of serve of the match in game 11 en route to taking the first set 7-5 but the Spaniard showed why he is world number one by responding brilliantly.