Updated

Five-time champion Serena Williams and three-time runner-up Maria Sharapova were a pair of fourth-round winners Monday at the $4.828 million Sony Ericsson Open.

The 10th-seeded former world No. 1 Williams exacted some revenge on Samantha Stosur by handling the sixth-seeded Aussie 7-5, 6-3 on Day 7. The Aussie Stosur stunned the powerful American in last year's U.S. Open finale.

Williams assumed control in the second set by breaking Stosur for a 4-2 lead. The American closed out the bout three games later by holding her serve, as Stosur sent a helpless return wide of the court on Williams' third match point.

The 30-year-old Williams uncorked 20 aces en route to victory.

The 13-time Grand Slam champion titled here from 2002-04 and 2007-08 and was the Miami runner-up in 1999 and 2009.

Meanwhile, the second-seeded former world No. 1 Sharapova snuck past fellow Russian Ekaterina Makarova 6-4, 7-6 (7-3) in 2 hours, 13 minutes at Crandon Park. The three-time Grand Slam champ moved on despite piling up 11 double faults.

Sharapova was the Miami runner-up in 2005, 2006 and last year, when she lost to current No. 1 Victoria Azarenka in the final. She was also this year's Aussie Open runner-up to Azarenka and last year's Wimbledon runner-up to Petra Kvitova.

Fifth-seeded Pole Agnieszka Radwanska rolled past Spanish wild card Garbine Muguruza Blanco 6-3, 6-2, while seventh-seeded Frenchwoman Marion Bartoli reached the quarters by pasting 22nd-seeded Russian Maria Kirilenko 6-1, 6-2 in 66 minutes. The former Wimbledon runner-up Bartoli fired seven aces and broke Kirilenko six times.

This week's big winner will collect $712,000.