INDIAN WELLS, California (AP) – World number one Rafael Nadal battled back from losing the first set against 239th-ranked Ivo Karlovic to reach the semi-finals at Indian Wells.
The Spanish top seed on Thursday clinched a 5-7, 6-1, 7-6 (9/7) win on his third match point in the third set tiebreak when the Croatian smacked a forehand long to end the match lasting nearly two-and-a-half hours.
"It was a very tight, difficult match," said Nadal, a two-time former winner of the tournament. "If you lose a set against Karlovic then you are under pressure for the rest of the match.
"In the third set his serve was unstoppable. In the tiebreaker I was really nervous. For sure it is a big day for me to be in the semi-final."
Nadal, who will be playing in his sixth consecutive semi-final at the tournament, will play Argentina's Juan Martin del Potro next, who progressed without even taking to the court after Tommy Robredo withdrew with an injury.
Del Potro said he was glad to be in the semi-finals and looked forward to locking horns with Nadal again.
"We make very good matches before, so I have two days to be better, in good form, and hopefully I can play 100 percent."
Robredo's surprise exit came after the Spaniard injured his left abductor muscle during his fourth-round match against Sam Querrey.
Del Potro, the 2009 US Open winner, has been one of the in-form players on the tour this year going into his first Indian Wells semi-final.
Nadal has a 4-3 edge over del Potro in career matches but the Argentinian has won the last three times they have met.
On women's side, top seed Caroline Wozniacki, whose opponent pulled out with a painful injury, eased into the semi-finals where she was joined by Maria Sharapova.
Wozniacki, of Denmark, was ahead 3-0 when Victoria Azarenka packed it in after taking a lengthy medical timeout to receive treatment for an injury to the left side of her hip.
The eighth seed Azarenka suffered the setback just 10 minutes into the match on the second point of the third game while stretching to try and return a shot.
World number one Wozniacki, who is good friends with Azarenka, said she was sorry to have to win that way.
"Victoria is one of my best friends on the tour, and to see her in pain on the court and to see her get injured was not nice for sure," Wozniacki said. "I would like to have won it in another way, but I'm through to the semi-finals."
Wozniacki moves on to play three-time grand slam champion Sharapova who defeated China's Peng Shuai 6-2, 5-7, 6-3 in a two-hour, 22-minute marathon quarter-final.
Wozniacki beat Azarenka for the fourth time in six career meetings and has now reached the semi-finals in her last four tournaments.
Sharapova won her quarter-final despite committing 13 double faults and winning just 27 percent of her second-serve points.
Neither player could hold serve at the start of the deciding set but then Sharapova found a spark in the sixth game to hold serve for the first time in the set and level the score at 3-3. Sharapova also won the next three games to take the match.
Sharapova, who called for her coach to come down to the court several times, broke Peng's serve four times in the third set, including the final game of the match to earn her ninth match win of the season to go with three losses.
"I played well in the first set and a half and then my level dropped," Sharapova said. "It was important to stay tough out there because you know the match isn't over until the last point."
Sharapova, who is the lone former Indian Wells champion left in the women's draw, now holds a 2-1 edge over Peng in career matches.
"Was really happy to into the quarterfinal here, but Maria is a tough match," Peng said. "In the third set I have chance, but she play well."
