Miami, FL (SportsNetwork.com) - Fresh off her big title at Indian Wells, third-seeded Simona Halep remained hot with a second-round victory Friday at the $5.3 million Miami Open.

The 2014 French Open runner-up got past Czech comeback kid Nicole Vaidisova 6-4, 2-6, 6-1 on the hardcourts at Crandon Park. The 25-year-old former top-10 star Vaidisova returned to the WTA this year after retiring from the sport back in 2010.

The sizzling 23-year-old Romanian Halep has now won 11 straight matches and is a brilliant 20-1 for the season, with her lone setback coming in the quarterfinals at the Australian Open in January. She's seeking her third title in her last three events.

Up next for Halep will be capable Italian Camila Giorgi.

A battle of former world No. 1s saw unseeded Victoria Azarenka dismantle 20th- seeded Jelena Jankovic 6-1, 6-1. The 2008 Miami champion Jankovic was fresh off her runner-up finish to Halep last week in the California desert.

Azarenka was the 2009 and 2011 Miami titlist.

A top-10 upset came when Swedish veteran Johanna Larsson doused Czech No. 10 seed Lucie Safarova 7-6 (7-5), 6-2.

Meanwhile, Sloane Stephens upended 17th-seeded fellow American Madison Keys 6-4, 6-2 and promising 15-year-old American CiCi Bellis also posted an upset by tackling 29th-seeded Zarina Diyas of Kazakhstan, 6-2, 6-1.

Also on Day 4, rising 21st-seeded Spaniard Garbine Muguruza drilled Kazakhstan's Sesil Karatantcheva 6-1, 6-3, 24th-seeded Russian and 2006 Miami titlist Svetlana Kuznetsova pasted American Alison Riske 6-2, 6-2 and the 30th-seeded Giorgi whipped Belgian Alison Van Uytvanck 6-3, 6-2.

The 2015 Miami champ will earn $900,400.