Ymer, 23, 83rd player in the world, had a hard time getting rid of Gasquet, three-time winner of this tournament and beaten in three sets on Friday, 7-5, 6-7 (6/8), 6-1.
The older one did well to take the second set in the tiebreak but then collapsed in the final set.
Never two without three: Gasquet is the third Frenchman in a row beaten by Ymer this week, since the Swede had first eliminated Corentin Moutet 7-6 6-4 on Tuesday, then Gaël Monfils, also three times victorious in Montpellier, in two sets Thursday, 6-1, 6-2.
In the last quarter-final, Zverev, 3rd player in the world, made short work of Mannarino, 33, 58th in the world, swept away 6-1, 6-0 in less than an hour.
In the semi-finals, Zverev will face Ymer on Saturday.
The other half will oppose the Serbian Filip Krajinovic, seeded N.5, who beat in the quarters the Bosnian Damir Dzumhur 7-5, 6-2, to the Kazakh Alexander Bublik (N.6), who eliminated the Spaniard Roberto Bautista Agut (N.2) in the decisive game of the 3rd set, with the score of 6-4, 2-6, 7-6 (7/4).
© 2022 AFP