MIAMI, FL, USA - 2012 champion Agnieszka Radwanska stunned Simona Halep at the Miami Open, coming back from a set down to knock out the World No.1.

Despite not posting back-to-back victories since January, No.30 seed Radwanska found her form to win 3-6, 6-2, 6-3, handing Halep her first ever defeat in Miami to a player ranked outside the Top 20.

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“I expected a tough match from Simona, so I’m just glad I could win a match like this,” Radwanska said afterwards. “There were pretty tricky conditions and some weird shots, but I’m very, very happy with the way I played, especially at the end. And to beat the No.1 in the world, obviously.”

The pair kicked off their eleventh career meeting by trading breaks, with Radwanska recovering from 0-2 down. Halep broke again to get ahead 4-1, but an error strewn game from her side of the court put them right back on serve.

Parity didn’t last too long, though, as Radwanska - who only held her serve once in the the opening set - wasn’t able to consolidate the break. Ten of her 18 unforced errors came in the first set alone too, and Halep took advantage of the free points to snatch away the set.

It was a different story in the second set as Radwanska began on a tear, dropping just four points in the opening four games to break twice and open up a 4-0 lead. As Halep’s frustration mounted, so did her unforced errors, as the Romanian tried to close out points too quickly and ended up overcooking her shots.

Halep was able to grab one of the breaks back at 4-1, but found herself immediately under pressure again, facing two break points. Radwanska broke again late in the second to take the set, sending the match into a third.

The Romanian got off to a break lead to start the final set 2-0, but her frustration and unforced errors - 44 in total against 31 winners - proved to be her undoing. Radwanska broke straight back, reeling off six of the last seven games of the match to claim the victory after an hour and 48 minutes.

The victory is Radwanska’s second career win over a World No.1, and the first since 2012. She extends her great record in Miami, too; she’s now reached the round of 16 or better in ten of her 12 appearances.

Up next, Radwanska will take on former World No.1 Victoria Azarenka, who took down No.20 seed Anastasija Sevastova. Azarenka holds a 12-5 lead in the pair’s head-to-head record.

“We haven’t played for a very long time, but I’ve played so many matches against her,” Radwanska recalled. “I think we’ve played on every possible surface and in every tournament!

“She’s one of the best players in the world and she’s always going to be. Playing her, I really have nothing to lose so that’s going to push me 100%.”