DOHA — Simona Halep won five games in a row in the deciding set of an astonishing match against Elina Svitolina in Doha on Friday to power through to the Qatar Open final.

Seemingly down and almost out at 1-4 in the third set, world number three Halep was roared on by a large and noisy set of Romanian fans to secure a remarkable 6-3, 3-6, 6-4 victory over the Ukrainian.

She will play Belgium's Elise Mertens in Saturday's final after the world No. 21 surprisingly beat three-time Grand Slam champion Angelique Kerber 6-4, 2-6, 6-1 in the other last four match.

Halep described her dramatic win as "unbelievable"."I didn't give up, I promised myself I would never give up against her again because I lost two matches very bad," said Halep.

She added: "She played amazing. She moved very well, she hit the ball strong, she didn't miss much. So I think was at a very high level of tennis today, and I'm really proud that I could win the match against her."

It was her first win against the world number seven since 2017. The Romanian will now play her 34th career final and will rise to the rank of No. 2 in the world whatever the result.

Mertens' victory was the second time this week she has beaten a player in the top 10, having dispatched world No. 8 Kiki Bertens in the quarterfinals.

The Qatar final will be her sixth singles' career final and she has only lost one of those, in Turkey in 2017 to Svitolina.

On Thursday, Halep and three-time Grand Slam champion Kerber came through tough tests to reach the semifinals.

Also through were Svitolina and e Mertens, providing some comfort for tournament organizers who have somehow ended up with three of the world's top 10 in the last four, despite a high number of prominent withdrawals.

Halep won in straight sets but needed two tie-breaks — 7-6 (7-1), 7-6 (8-6) — to edge past Germany's Julia Goerges, despite racing to a 4-0 lead in the first set.

However, the match turned out to be anything but routine for the Romanian who was forced to save two set points and break Goerges' serve in the 10th game to stay in the second set. "I am very happy, honestly," said Halep. "It's been a really tough match and it is always tough to play against her."

Svitolina was the first player through to the semifinals, beating Czech qualifier Karolina Muchova by contrast in easy fashion 6-4, 6-2. She was followed on court by Kerber, the world number six, who won 1-6, 6-2, 7-6 (7-4) in a tough and feisty encounter against another Czech, Barbora Strycova, who was given a time violation in the final set. It will be Kerber's first semifinal since she won at Wimbledon last year. She was slated to meet Mertens, the world No. 21, in the last four, who beat Kiki Bertens of the Netherlands 6-4, 6-3. — AFP