JOIN USNadal to take on Roddick in semis
Roddick cruised with a 6-3, 6-3 win over Spain's Nicolas Almagro while Nadal was in blistering form in front of a packed crowd as he crushed France's Jo-Wilfried Tsonga 6-3, 6-2.
The big serving Tsonga matched Nadal in the opening exchanges but never recovered after the Spaniard broke his serve in the seventh game of the opening set.
From then on Nadal was in outstanding form, displaying his full range of strokes as he dealt with everything that Tsonga threw at him saving all eight break points in the match.
Nadal, always a favourite among the heavily Hispanic crowd in Miami, survived a crucial break point when he was 3-1 up in the second set but facing Tsonga's renewed determination and it was free cruising from that point.
Sixth seed Roddick, who won this event in 2004, never looked back after breaking at the first opportunity in the opening set. In the second Roddick broke in the fifth thanks to two great forehand shots down the line and a delicate half-volley.
But the American never really had to take any risks as he kept it tight and looked to take advantage of whatever loose returns came his way.
Henin versus Clijsters
Belgian pair Justine Henin and Kim Clijsters will meet in the semifinals after both advanced through their quarterfinal ties on Wednesday.
Henin took a step towards her third final since her comeback when she beat world number two Caroline Wozniacki 6-7, 6-3, 6-4.
She now has a chance to avenge her defeat to Clijsters in January's final of the Brisbane Open after her long standing rival beat Australian Samantha Stosur 6-3, 7-5.
Henin, a nine-times Grand Slam winner who entered the tournament as a wildcard, recovered from losing the opening set by getting the upper hand in the second and a single break in the third was enough to take her through to the semi-finals.
Henin broke in the eighth game of the second set to get back on level terms. Then she broke the third game of the final set and although Wozniacki showed plenty of determination and application, the Belgian was in no mood to give up.