WASHINGTON, April 2 (Xinhua) -- Argentine Juan Martin Del Potroscored a surprising 6-4, 3-6 and 7-6 victory over world number one Rafael Nadal of Spain to reach the semi-finals of the Miami ATP hard court tennis tournament on Thursday.

Rafael Nadal of Spain reacts after losing a point during his match against Juan Martin Del Potro of Argentina at the Sony Ericsson tennis tournament in Key Biscayne, Florida April 2, 2009.(Xinhua/Reuters Photo) Photo Gallery>>>

    Del Potro, 20, who came back from 3-0 down in the third set for the win, his first over Nadal in five attempts, will face either Britain's Andy Murray or Spain's Fernando Verdasco for a place in the final.

    "I played really bad all the time. That's the truth of this match," said Nadal, "Later when I was 3-0 up in the third I played worse. I had the match, it was amazing disaster."

    Del Potro, who lost to Nadal in Indian Wells last month, was roared on by hundreds of Argentinian fans when he broke in the first set to go 5-4 up.

Rafael Nadal of Spain leaves the court after losing his semi-final match against Juan Manuel Del Potro of Argentina at the Sony Ericsson Open tennis tournament in Key Biscayne, Florida April 2, 2009. (Xinhua/Reuters Photo) Photo Gallery>>>

    After winning the opening set, Del Potro broke early in the second but the Spaniard played some powerful strokes to win the second.

    Nadal looked on course for victory when he broke twice in the third to go 3-0 up. But Del Potro found the strength, broke back twice to go to 3-3with cross-court drive.

    Both players then stuck to the baseline. At 6-5 to Del Potro, Nadal was 40-15 down, he saved three match points to deuce before Del Potro hit the net and the set was tied at 6-6.

Juan Martin Del Potro of Argentina wipes his face on his country's flag after defeating Rafael Nadal of Spain at the Sony Ericsson tennis tournament in Key Biscayne, Florida April 2, 2009.(Xinhua/Reuters Photo) Photo Gallery>>>

    In the tiebreak, from 2-2, Del Potro found another burst of power to take next five points to win.