Raonic came from a set down to oust defending champion Richard Gasquet 3-6, 7-5, 6-4 on Saturday and reach the final of the Thailand Open.
The hard-serving Raonic hit 23 aces and broke Gasquet once in each of the second and third sets, but wants to play even better against top-seeded Tomas Berdych on Sunday.
"There are things I must do better for sure tomorrow," said the 22-year-old Raonic. "I competed well but he played better and had more opportunities in the first set."
Raonic, from Thornhill, Ont., recovered nicely against Gasquet after dropping the opening set with what he admitted was a less-then-perfect initial effort. The two are familiar opponents — Gasquet beat Raonic in a tight U.S. Open fourth-round match lasting five sets and more than four and a half hours.
Raonic took a 4-3 lead in the final set on Saturday as he saved a break point with his 19th ace and won the game with his 20th. Gasquet answered with a love game before Raonic broke him to earn victory two games later on the second of three match points.
"The first set was not so much about me losing as it was about him playing well. He did a lot to win it and hardly made an unforced error," said Raonic. "But I kept focus on my serve, which I knew was the way I was going to turn things around."
Berdych needed nearly three hours to outlast Gilles Simon of France 6-7 (5), 6-2, 7-5.
Simon saved four set points in the 10th game of the first set and was down 5-3 in the tiebreaker before winning the next four points, clinching it when Berdych sent a forehand into the net.
But Berdych took a 3-0 in the second and broke his opponent in the 11th game of the decider to reach his third final of the year.
Raonic knows the challenge he faces in world No. 6 Berdych.
"It will certainly be a tough match," said Raonic. "I think it will be about who can control points earlier and who can dictate and control the centre of the court more."
If Raonic wins, it will be his fifth career title and second of the season after winning a third trophy at the now-defunct San Jose event. His other title came at Chennai, India, last season. He has 26 wins and 17 losses this season.