Russia's Anastasia Pavlyuchenkova finally reached a Grand Slam semifinal at the 52nd time of asking as she beat Kazakhstan's Elena Rybakina 6-7(2) 6-2 9-7 at the French Open.
Six times the 29-year-old had lost at the quarter-final stage of one of the four majors, but she used all her experience to overcome her doubles partner in a gruelling scrap.
Rybakina, 21, looked in control of her first Grand Slam quarter-final when she opened up a 4-1 lead in the first set but Pavlyuchenkova hit back to force a tiebreak.
Pavlyuchenkova took the momentum into the second set to level the match and kept her nose ahead in a tense finale.
Rybakina, who beat Serena Williams in the fourth round, held serve three times to stay alive in the third set.
But she failed at the fourth time of asking, ending the contest in tame fashion with a double-fault.
Pavlyuchenkova will face fellow semi-final debutant Tamara Zidansek for a place in Saturday's final after the Slovenian also came though a long battle, against Paula Badosa.
Tournament surprise package Zidansek prevailed in a dramatic battle with Badosa to reach the semi-finals.
The Slovenian, who had never previously been beyond the second round at a grand slam, was the outsider of the unexpected quarter-final line-up but she held her nerve when it counted to win 7-5 4-6 8-6.
Zidansek looked poised for a more comfortable victory when she led by a set and a break but Badosa fought back and led early in the decider.
The Spaniard was also playing in her first slam quarter-final but she has won more matches than any other woman on clay this season and went into the tournament as a dark horse.
That pressure was evident for a set and a half, with Badosa struggling to play freely while Zidansek handled the occasion superbly.
The 23-year-old reached the final of a clay-court tournament in Colombia in April so had some form behind her but, at 85 in the rankings, she is certainly one of the more unexpected slam semi-finalists of reason years.
From a set and 4-2 down, Badosa began to make her power count and a run of six games in a row put her in the ascendancy. But back came Zidansek and a forehand winner gave her victory on her second match point after two hours and 26 minutes.