INDIAN WELLS, California — Cracking winners off his forehand in key moments, Juan Martin del Potro defeated top-ranked Novak Djokovic 4-6, 6-4, 6-4 in the semifinals of the BNP Paribas Open Saturday, handing the Serb his first loss in 21 matches dating to last October. Del Potro snapped his own four-match skid against Djokovic, who had beaten the Argentine in eight of 10 career meetings. “I'm trying to hit hard with my forehands. When I have the chance to come to the net, I did all the time,” he said. “I was just focusing to put in my first serve and move to my forehands, trying to make winners.” Del Potro's 133-mph ace closed out the nearly 3-hour match featuring nine breaks of serve in 96-degree heat. He raised both arms in celebration and Djokovic hugged him at the net. Del Potro, the second Argentine to reach the final here, will play Rafael Nadal for the title Sunday. They each have three wins against each other on hard courts. No. 2 seed Maria Sharapova and No. 8 Caroline Wozniacki will play in the women's final. At times, the unseasonable heat seemed to have worn down Del Potro, who draped a white towel packed with ice around his shoulders on changeovers, his chest heaving from several long rallies. Del Potro was coming off a three-set win over Andy Murray in similarly hot conditions in Friday's quarterfinals. The heat — nearly 20 degrees above the average of 78 — also affected Djokovic, as did the shadows that eventually overtook the court as the afternoon wore on. He blew a 3-0 lead in the final set, and from there, Del Potro won six of the last seven games. Djokovic attributed Del Potro's dramatic turnaround to “his fighting spirit and my lack of concentration.” Nadal rallied to beat Tomas Berdych 6-4, 7-5 in the other semi and reach his fourth ATP Tour final in as many events. Off to the best start of his career, Nadal improved to 16-1 — including 13 wins in a row — on the year, having won two clay-court titles and been runner-up in another since returning from a left knee injury that idled him for seven months. It was Nadal's 12th straight win over Berdych, including seven consecutive on hard courts. Top-seeded Bob and Mike Bryan won the men's doubles title for the first time in 14 tries, defeating Treat Huey of the Philippines and Jerzy Janowicz of Poland 6-3, 3-6, 10-6. — AP