Key Biscayne: World number two Rafa Nadal was pushed all the way by France's Jo-Wilfried Tsonga before finally emerging with a 6-2, 5-7, 6-4 victory to earn a place in the semi-finals of the Sony Ericsson Open on Wednesday.   

Nadal next faces fourth-seeded Briton Andy Murray, who rallied for a 4-6, 6-3, 6-4 win over Serbian Janko Tipsarevic.   

After winning his first set comfortably, Nadal was within two points of victory in the second but then the towering Tsonga began his brave resistance.   

Tsonga broke, helped along by an untimely double-fault from Nadal and then claimed the set with a magnificent forehand return winner.   

The third set produced some highly entertaining tennis and the Frenchman combined explosive shots, deft slices and glorious backhand work around the net to stay in touch with the Spaniard.   

Tsonga came close to breaking in the sixth game but Nadal held his nerve and for all the ebbs and flows of what had become a real battle, the pair remained on serve until the ninth game   

Nadal made the decisive break when Tsonga failed to keep a cross-court forehand in play and although the Frenchman staved off matchpoints, the second seed claimed the two hour, 49 minute contest when his opponent dumped another forehand into the net.   

Medical Attention   

Murray also endured a scare as the world number four trailed by a set and a break before receiving medical attention for what appeared to be a stomach problem.   

The Scot then promptly turned the match around as he broke the next service game from ninth seed Tipsarevic and went on to clinch the second set.    

Murray, whose backhand was below par as he made 34 unforced errors, then broke in the third game of the final set and held firm with his serve to ensure a last-four showdown against Nadal.   

Murray said after the game that his health problem was almost certainly related to over-hydrating before the game.   

"I have this thing that tests how hydrated you are, which I used that for the match, and (afterwards) I was very hydrated, even though I'd drunk nothing the last couple of sets.     

"So I don't know if I drunk too much beforehand and kind of overhydrated and my stomach was filled with liquid. Each time I took a sip I wanted to burp, basically.    

"I drank very, very little the last two sets. I mean, must have been something to do with that. It was so hot and humid, and to come off the court hydrated after not really drinking would probably suggest that I had drunk way too much."