British number two Dan Evans was beaten by Pablo Carreno Busta in the Canadian Open semi-finals in Montreal.
Although Evans became the first player to take a set off the Spaniard in the tournament, he lost 7-5 6-7 (7-9) 6-2 in almost three hours.
Carreno Busta, ranked 23rd in the world, will play Poland's Hubert Hurkacz in his first ATP Masters final.
Hurkacz dropped his first set before fighting back to beat Casper Ruud of Norway 5-7 6-3 6-2.
In the women's event in Toronto, Romania's Simona Halep reached the final with a 2-6 6-3 6-4 victory over American seventh seed Jessica Pegula.