'S-HERTOGENBOSCH, Netherlands (Reuters) -Belgian third seed Elise Mertens dug deep to save 11 match points and overcame twice winner Ekaterina Alexandrova 2-6 7-6(7) 6-4 to reach the Libema Open final in Den Bosch on Saturday, where she will face qualifier Elena-Gabriela Ruse.

Mertens found herself 5-3 down in the second set after losing the first but battled back to force a tiebreak before seeing off the Russian second seed who was aiming to win her third title having triumphed in 2022 and 2023.

"I didn't even know it was 11, after one or two I lost count," Mertens said.

"It was a difficult match, I think she started really well, and it was 6-2, 5-3 for her. I just stayed with my head in the game and gave everything I had."

Alexandrova won their only previous meeting in Den Bosch, in 2019, and has reached at least the quarter-finals of the last five editions, but Mertens now has the chance to win a second title this year, after her Singapore triumph in February.

Standing in Mertens' way will be Romanian Ruse who recovered from losing the first set to defeat Italian Elisabetta Cocciaretto 2-6 6-4 6-3. Mertens has won all three previous meetings with Ruse.

Ugo Humbert, the only seed left in the men's draw, crashed out to Gabriel Diallo, with the Canadian defeating the French second seed 6-3 7-6(4) to advance to the final where he will meet Belgium's Zizou Bergs.

Diallo broke to love to lead 5-3 and held serve to take the opening set. Humbert saved two break points with the second set delicately poised at 5-5, but Diallo came out on top in the tiebreak as he bids to win his first ATP Tour title.

Bergs is also on the hunt for his maiden ATP win, and had little trouble overcoming lucky loser Reilly Opelka 6-1 6-4, with the American perhaps still feeling the effects of his battling win over top seed Daniil Medvedev on Friday.

The Belgian stormed to the first set, winning five consecutive games, and while Opelka regained his composure in a more even second set, Bergs made the decisive break to lead 5-4 and served out for the match.

Bergs and Diallo met for the first time at this year's Madrid Open, where Diallo eased to a straight-sets win in the first round.

(Reporting by Trevor Stynes, editing by Pritha Sarkar and Ed Osmond)