Frenchman Jo-Wilfried Tsonga achieved a straight-sets victory over Mardy Fish at the ATP World Tour Finals this afternoon.

Having lost to Roger Federer on Sunday afternoon, Tsonga kept his hopes of qualifying for the semi-finals alive while all but ending his American opponent's chances of progressing.

Both players found it difficult to hold their serves during the early exchanges, with the first four games going the way of the receiver.

The set headed into a tie-breaker, which Tsonga controlled throughout to record a 7-4 success.

World number eight Fish appeared to be hampered by a persistent hamstring injury in the next set as he was only able to hold his serve on one occasion.

Tsonga capitalised to wrap up the match 7-6[4] and 6-1.