Juan Martin Del Potro boosted his hopes of reaching the semi-finals of the Barclays ATP World Tour Finals with a crushing 6-0 6-4 victory over Janko Tipsarevic.

Del Potro, from Argentina, lost to David Ferrer in his first match so badly needed a good win to keep him in contention, and he will reach the semi-finals if he beats Federer tomorrow.

The defending champion (pictured) secured his progress from Group B with a straight-sets win over Ferrer. The Swiss said: "I think it's a great victory for me."