Pablo Carreno Busta was a surprise first-round casualty at the Rotterdam Open after falling to Richard Gasquet on Monday.

World number 16 Carreno Busta, the seventh seed at the ATP 500 event in the Netherlands, took the first set with ease but fell to a 2-6 7-6 (7-2) 6-2 defeat against Frenchman Gasquet.

Veteran Gasquet, ranked 45th in the world, will next meet Stan Wawrinka after the Swiss overcame Alexander Bublik in dominant fashion with a 7-6 (7-5) 6-4 triumph.

Grigor Dimitrov recorded a 6-1 6-3 victory over Aslan Karatsev in just 59 minutes to set up a potential second-round tie with fifth seed Hubert Hurkacz, who must first get past Roberto Bautista Agut.

Qualifier Gregoire Barrere was another straight-sets winner, defeating David Goffin 6-0 7-6 (7-3).

The Frenchman, who is ranked 71st in the world, could meet third seed Felix Auger-Aliassime in the next round if the Canadian overcomes Italy's Lorenzo Sonego.