CHARLESTON, S.C. - Angelique Kerber rallied past Madison Keys to win the Family Circle Cup on Sunday, capturing six of the last seven games for a 6-2, 4-6, 7-5 victory.

This was Kerber's fourth WTA title and first since Linz in 2013. The German broke serve five times against an opponent who hadn't lost serve all week.

Kerber fell to the ground and covered her face in celebration when Keys' final shot sailed long. Kerber had defeated friend, countrywoman and defending champion Andrea Petkovic in the semifinals.

Kerber trailed 4-1 in the final set, with the 20-year-old American using a strong serve to build what looked like a solid lead. The German won 12 of the next 16 to tie the match. Keys moved in front once more at 5-4 before Kerber took control for good.

Kerber won the next game at love, then rallied from 40-0 down to break serve and pull ahead. Keys made four straight errors in the final game to give Kerber the match.

Keys, seeded seventh, entered the final on a strong run. She had dominated four opponents in reaching her first clay-court final. But Kerber was just as relentless at keeping the ball in play and counting on Keys' aggressiveness to lead to mistakes on the slow surface. Keys finished with 57 unforced errors, nearly three times as many as Kerber's 21.

Kerber broke serve three times in a surprisingly quick opening set. Keys found her footing in the second set to tie the match. She moved Kerber from side to side and used her powerhouse forehand to gain control. That continued into the third set and she built a 4-1 lead.

Keys consistently hit serves topping 100 mph. Her consistency, though, didn't match Kerber's. Keys made only 66 per cent of her first serves while Kerber proved steady at 83 per cent.

It was the second straight knockdown final for Keys and Kerber. Keys outlasted the German in three sets to win her only WTA title, at Eastbourne last June.