Second seed Rafael Nadal out-fought Juan Ignacio Chela 7-5 7-5 to reach the semi-finals of the Pacific Life Open on Thursday.
In a tight contest where both men launched huge stokes from the baseline, twice French Open champion Nadal was much more secure competing in the big points.
The Spaniard forced the Argentine into a backhand error to break him to 6-5 in the second set and won the match when Chela committed a backhand error.
Nadal will face the winner of the match between third seed Andy Roddick of the U.S. and eight-seeded Croatian Ivan Ljubicic of Croatia.
In the women's section, Russian second seed Svetlana Kuznetsova clawed back to a 4-6, 6-3, 6-4 win over Czech Nicole Vaidisova in the quarter-finals.
