Defending champion Maria Sharapova on Saturday booked her place in the final of the Stuttgart WTA tournament after seeing off Germany's Angelique Kerber with a 6-3, 2-6, 7-5 victory in yet another three-set tussle.

The 26-year-old Russian has also been taken to three sets in both her previous matches, when she saw off Lucie Safarova, then Ana Ivanovic in Friday's semi, and showed some grit to see off Kerber, who was cheered on by the crowd. French Open champion Sharapova has played seven-and-a-half hours in her three matches here on clay, but comfortably took the first set with two breaks, before Kerber returned the compliment in the second. The third-set was a battle royal as the pair shared five breaks and third-seed Kerber refused to yield until the final phase of the 2hrs, 16mins match. The German played some great line shots to frustrate the Russian and level at 5-5 before Sharapova held her serve, then used her third and final break to take the match.

"All credit to Angelique, she played a great match," said Sharapova, who won last year's tournament here on her Stuttgart debut before going on to win the fourth Grand Slam title of her career at Roland Garros. "I won this tournament last year on the way to the French Open so I am really pleased to get back into the final again." In Sunday's final, Sharapova will face either second-seed Li Na ofChinaor qualifier Bethanie Mattek-Sands of theUSA, ranked 104th in the world, who has made it through to the semi-finals on her first appearance in the main draw. Sharapova has never lost to Mattek-Sands in their five previous meetings, but Li won their last match in January's Australian Open semi when the Chinese won 6-2, 6-2; her fifth win over the Russian, who has beaten her eight times.