Spanish tennis continues its assault on the Miami tournament, this season's second Masters event, with both Rafael Nadal and Fernando Verdasco through to the quarter finals.

Nadal did not have an easy time of it last night against a steadfast Stanislas Wawrinka, but finally pulled off a 7-6 (2), 7-6 (4) victory after two hours and 43 minutes on court.

The Swiss player had the Spaniard on the ropes on more than one occasion in what was, on the whole, a very even contest, but Nadal managed to come through unharmed, his fighting spirit and supreme concentration proving decisive on the important points.

Nadal's next opponent will be the Argentine Juan Martín Del Potro, who easily defeated Spain's David Ferrer 6-3, 6-2, earlier in the day.

Verdasco had a much more convincing win to book his place in the quarter finals, seeing off the Czech player, Radek Stepanek, 6-2, 6-2.

It is the first time in his career that Verdasco has made the quarter finals of the Miami tournament and Britain's Andy Murray awaits him in his next match. 

Murray made light work of the Serb, Victor Troiki, demolishing him 6-1, 6-0 without conceding a single break point.

The remaining quarter finalists are Jo-Wilfried Tsonga, who is up against world number three, Novak Djokovic and Roger Federer, who will take on the American, Andy Roddick.