Jo-Wilfried Tsonga looks a very good pick for an upset win in the quarters.

Rafael Nadal has been walking a tightrope through to the quarter-finals, teetering on the brink of an early exit in both his second and third round matches. Luckily for him, Nicholas Almagro and Tommy Robredo lacked the necessary poise to close the matches out and Nadal has survived but only just.

He saved 5 match points against Almagro and Robredo served for the match before losing 6-3, 3-6, 7-5. In contrast, Tsonga has won both his matches in straight sets, defeating an injured Gilles Simon 6-2, 6-3 on Thursday. He poses a much more formidable obstacle than either of Nadal’s opponents so far, with more power than Robredo and better movement than Almagro.

Nadal will be wary, he leads the head-to-head 3-1 but he knows what an inspired Tsonga is capable of. He was crushed in the semis of the 2008 Australian Open and Tsonga should have repeated the treatment in Indian Wells a few months later but choked.

It’s possible that this match will bring the best out of Nadal but like Federer and Murray he has looked very jaded, even sluggish this week and his groundstrokes have been strangely inconsistent.

The bookies are recognizing Nadal’s poor form and Boylesports have Tsonga as the favourite at 8/11 with Nadal at 11/10.