INDIAN WELLS, CA, USA - The list of first for Bianca Andreescu keeps getting longer.

The 18-year-old Canadian rallied from a set down to defeat Irina-Camelia Begu in the first round of the BNP Paribas Open on Wednesday, 6-7(3), 6-3, 6-3 for her first career win at the Premier Mandatory event.

The World No.60 was slow out of the gates in her tournament debut against her experienced foe, as she trailed 4-0 and 5-2 in the opening set only to eventually fall just short of a complete turnaround, but broke Begu five times across sets two and three to score victory. 

"For me, the ending is the most important, so I'm really glad I pulled through," Andreescu said after the match. 

"Mentally...I was like, I might as well go for my shots, and see where that leads me and that's what I did, and it worked. When I take control right from the start of the point, I win most of my points. 

Today, that didn't really show in the first set, so I had to change somrthing. That's what happened, and it worked." 

Andreescu captured the last five games from 3-1 down against the World No.70 to avenge a three-set defeat from their first career meeting, which came in national competition in Fed Cup last season. 

"She played exactly the same. I wanted to go more to her forehand, because I feel she hits the ball a bit more short on her forehand than on her backhand. She likes to take control with her backhand," the Canadian assessed. 

"I tried to use my serve to my advantage, because I know she has a good serve. I played the big points better than her, and more consistent. I was opening up the court, and I just fought really hard."

The victory for Andreescu, which is her tour-leading 22nd of the season that includes qualifying and main draw matches, sets up a second-round clash against No.32 seed Dominika Cibulkova.

"It's my first time here, and I'm enjoying it a lot. I try to take every match like it's every other match, and if I do that, there's no pressure," Andreescu said.

"She's a fighter, runs to every ball and places the ball pretty well. I think if I play my game, stay aggressive right from the start, I can take her. I've gained a lot of experience in the past couple of months, so hopefully it shows. 

"I've been working so hard and I really believe in myself and my capabilities. I didn't expect all of this to come so quickly. I did expect to be at this level at one point in my life, so I guess it's better sooner rather than later."