Two-time Miami Open champion Victoria Azarenka began her tilt at a third crown in Florida in swift fashion, while seven qualifiers progressed past the first round on Wednesday.

Azarenka, unseeded after seeing her ranking slip to 36th, overcame a mid-match slip-up to down Silvia Soler-Espinosa 6-1 6-3 in a first-round encounter at the WTA Premier event.

Winner of the event in 2009 and 2011, Azarenka cruised to the first set against her Spanish opponent, but then trailed 3-1 in the second set as Soler-Espinosa threatened to send it to a decider.

But five straight games saw Azarenka dismiss that possibility, as she set up a clash with BNP Paribas Open finalist Jelena Jankovic.

Jankovic, seeded 20th in Miami, saw her season explode to life in Indian Wells where she reached her first Premier-level final since October 2013, despite a dry run to start her 2015 campaign.

Former world number seven Nicole Vaidisova won her first WTA-level match since 2010, the Czech defeating qualifier Timea Babos 6-1 7-6 (7-4) to launch the second phase of her career.

Czech Republic's Vaidisova is playing just her second event on the WTA Tour since February 2010, at which point she retired aged 20.

Next up for world number 328 is third seed Simona Halep, who comes to Miami on the back of her momentous title at Indian Wells.

In an all-Russian affair, Anastasia Pavlyuchenkova upended former world number two Vera Zvonareva 6-2 3-6 7-5.

No less than seven qualifiers progressed past the first round at the hard-court event, including Alison van Uytvanck, Tatjana Maria, Stefanie Voegele, Urszula Radwanska, Pauline Parmentier, Sesil Karatantcheva and Irina Falconi.

Van Uytvanck finished in a flurry over Magdalena Rybarikova 7-5 2-6 6-0, while Maria dealt Roberta Vinci a 7-6 (11-9) 6-3 defeat and Sesil Karatantcheva ousted Lauren Davis 6-3 7-6 (7-5).

Vinci recently parted company with Sara Errani as doubles partners to focus on her singles career, but the Italian veteran was unable to immediately capitalise on the move.

Falconi edged Monica Puig 7-6 (11-9) 7-6 (7-3), Parmentier came back to beat Kiki Bertens 4-6 6-2 6-3, Radwanska downed Coco Vandeweghe 6-4 6-7 (2-7) 6-3 and Voegele was too good for Kirsten Flipkens 6-2 6-2.

Julia Goerges had a resounding 6-1 6-0 win over Jana Cepelova, the latter winning just nine second-set points - although Mirjana Lucic-Baroni could only manage eight in her second set against Alison Riske, who triumphed 6-4 6-0.

Heather Watson blew a 5-2 third-set lead against Evgeniya Rodina, but recovered for a 3-6 6-1 7-5 victory over the qualifier.

Other qualifiers to bow out in the first round were Kateryna Kozlova, Alexandra Dulgheru and Marina Erakovic.

One-time Wimbledon semi-finalist Tsvetana Pironkova defeated Kozlova 6-4 6-3, while former world number 21 Elena Vesnina proved too good for Dulgheru 6-4 6-2.

New Zealander Erakovic was forced to retire injured while trailing Daria Gavrilova 5-1 in the first set, the wildcard progressing to a second-round clash with second seed Maria Sharapova.

Fellow wildcard Sorana Cirstea was not as fortunate, the Romanian losing 7-5 6-4 to Christina McHale.

Annika Beck edged a tight encounter with Zhang Shuai 6-4 4-6 6-4, while teenager Belinda Bencic got the better of veteran Daniela Hantuchova 6-1 7-6 (7-5) and Sloane Stephens defeated Yanina Wickmayer 6-1 6-3.