Shahar Pe'er crashed out of the Sony Ericsson Open in Miami on Thursday night, losing her semifinal encounter to Serena Williams 7-6 (4), 6-1. Williams struggled early against the 14th-seeded Pe'er, who came within two points of an upset when they met at the Australian Open in January. In the first set Williams returned poorly, struggled with her backhand and failed to break serve. She said she was bothered by a sore left knee. "It's a little tired," said Williams. "I forgot to take my anti-inflammatory medicine." Big serves kept Williams in the set. She won 12 consecutive service points to stay even, took a 4-1 lead in the tiebreaker and closed out the set with a service winner and a shout, "C'mon!" "I was very close," said Pe'er, who played in her first Tier I semifinal. "The first set could go either way. Unfortunately, the second set she was running away." Williams earned her first break early in the second set, took a 3-0 lead and punctuated the victory with her seventh ace. Playing her first tournament since winning the Australian title, she's seeking her fourth Key Biscayne title. With a 14-1 record this year, Williams will climb to at least 12th in next week's rankings. She was ranked as low as 140th in 2006, when she played in only four tournaments.