Serena Williams rallied to beat Victoria Azarenka in a French Open match filled with momentum swings and a contentious exchange between the two players.

Top seed Serena Williams was given a huge scare in her three-set win over Victoria Azarenka at the Madrid Open.

There is a growing feeling here that the greatest threat to Serena Williams' calendar-year Grand Slam is Victoria Azarenka, who defeated No. 11 seed Angelique Kerber 7-5, 2-6, 6-4 on Saturday.

Victoria Azarenka won a showdown between the world's two top players by beating number one Serena Williams in a three set 2-6 6-2 7-6 thriller in the final of the Western and Southern Open on Sunday.

Williams erased deficit after deficit and beat former No. 1 Azarenka 3-6, 6-4, 6-2 Saturday in a third-round French Open match filled with momentum swings and one GIF-ready contentious exchange.