Ash Barty will meet Aryna Sabalenka in the Stuttgart Open final after Simona Halep's quest to win the tournament for the first time fell short.

World number three Halep had claimed straight-set wins over Ekaterina Alexandrova and Marketa Vondrousova en route to the semi-finals, but met her match in the form of Belarusian Sabalenka, who triumphed 6-3 6-2.

A nine-time singles champion, Sabalenka made it into a 14th career final without conceding a single break, as she managed to keep Romanian Halep at arm's length.

Standing between Sabalenka and a 10th singles title is world number one Barty who, on her 25th birthday, came from behind to defeat Elina Svitolina 4-6 7-6 (7-5) 6-2.

Making her tournament debut in Stuttgart, Barty had overcome Laura Siegemund and Karolina Pliskova, but found herself at 5-4 down in the second set, with Svitolina serving for the match.

The fourth seed failed to take her chance, with Barty breaking and subsequently biting back in the tie-break, before carrying the momentum into the decider to claim a third straight win over Svitolina.

Top seed Elise Mertens made it to her second Istanbul Open as she saw off her doubles partner and birthday girl Veronika Kudermetova 6-1 6-4.

It means Mertens will be playing in two finals on Sunday, as she pairs up with Kudermetova again in the doubles showdown against Nao Hibino and Makoto Ninomiya.

Mertens' win ended Charleston champion Kudermetova's nine-match winning streak, and set up a final against the unseeded Sorana Cirstea, who defeated Marta Kostyuk 6-4 6-4.