Gael Monfils defeated Tallon Griekspoor 6–7 6–1 6–4 in the first round of the Monte Carlo Masters on clay on 5 April 2026, overturning pre-match odds that favoured Griekspoor. Despite dropping a tight opening set via tiebreak, Monfils regained control in the second and third sets, demonstrating improved consistency after a shaky start. Griekspoor, seeded or ranked higher going into the match, struggled to maintain the form that had made him the betting favourite, allowing Monfils to build momentum through the middle stages. The Frenchman's comeback victory suggests renewed confidence on his preferred surface and sets up a favourable trajectory through the tournament's early rounds.