Key Biscayne, FL (Sports Network) - Five-time champion Serena Williams secured a berth in the semifinals at the $4.195 million Sony Open tennis event on Tuesday.
The world No. 1 superstar got past fifth-seeded Australian Open runner-up Li Na of China 6-3, 7-6 (7-5) in 1 hour, 50 minutes on the hardcourts at Crandon Park. The American is now 7-1 lifetime against the former French Open champion Li.
The reigning Wimbledon and U.S. Open titlist Williams improved to 16-2 in 2013.
Williams will meet the Agnieszka Radwanska-Kirsten Flipkens winner in the round of four. The fourth-seeded Radwanska is the reigning Miami champ, having beaten recent Indian Wells winner and four-time Sony Open runner-up Maria Sharapova in last year's finale here.
The mighty Williams has appeared in seven Sony Open finals, including three straight titles from 2002-04 and back-to-back championships in 2007 and 2008.
Two other quarterfinals on Wednesday will pit the third-seeded former world No. 1 Sharapova against eighth-seeded Sara Errani and 15th-seeded Italian Roberta Vinci versus 22nd-seeded former No. 1 Jelena Jankovic. Sharapova beat Errani in last year's French Open final. Jankovic was a Miami finalist in 2008.
Sharapova is in the midst of a nine-match winning streak.