World number one Novak Djokovic booked a semi-final showdown with Juan Monaco at the Miami Masters by holding off a determined David Ferrer of Spain 6-2, 7-6 (7/1).
"It's always going to tough against David, he's one of the greatest competitors on the circuit," said Serbia's Djokovic, winner of the last three Grand Slams. "I didn't want to get to the third set because physically he's always there."
Defending champion Djokovic opened the match playing superb tennis, dictating the rallies and giving fifth-seeded Ferrer little opening and at one point winning 13 straight points.
He pocketed the first set in just 32 minutes and broke Ferrer in the first game of the second before the tenacious Spaniard turned the tables.
Ferrer broke back and was holding his own against the world's top player until a loose service effort from the Spaniard saw Djokovic break for a 5-4 lead and a chance to serve out the match.
Ferrer denied him as they battled to the tie-breaker, where Djokovic claimed a quick advantage as Ferrer swatted an ill-judged forehand into the net to fall behind on his serve on the first point.
Djokovic was firmly in control from there as he advanced to a meeting with Monaco, who celebrated his 28th birthday by surprising eighth-seeded American Mardy Fish 6-1, 6-3.
"I can't believe it," said Monaco, the 21st seed. "I have a lot of emotions, it is good to celebrate this way, playing unbelievable tennis on my birthday.
"Every shot I wanted to play I did. It was a perfect match for me. I returned well and then I served very, very good."
Fish broke Monaco in the sixth game of the second set to make it 3-3 but Monaco responded by winning three straight, closing it out on the first of three match points with a backhand drop shot.
This is Monaco's ninth appearance in Miami but the first time he has reached the semis.
Fish said Monaco's all-around game was just too much for him.
"He did a lot of things well and I think more than anything else, he shrunk the court extremely well with his movement and that's why I think you saw a ton of errors from me," the American said. "I was pressing a lot just because he wasn't giving me anything."