MIAMI — Everything was completely different for Bianca Andreescu at the Miami Open on Thursday compared to her victory in the final of the BNP Paribas Open on Sunday in Indian Wells, Calif.

Except for one thing: the 18-year-old Canadian's fight and determination.

Andreescu was nearly out in the first round at the hands of Irina-Camelia Begu on Thursday, in a match postponed from the night before because of rain. The product of Mississauga, Ont., was down a set, and down 5-1 in the second set before pulling out a 4-6, 7-6 (2), 6-2 victory that puts her in the second round against No. 32 seed Sofia Kenin of the U.S.

There won't be much time to rest as that match will be played Friday afternoon.

The surface in Miami is different than the one in Indian Wells, much quicker. The conditions were different too, being warmer and much more humid.

Even the cheering section was different. Andreescu's parents, Nicu and Maria (and dog Coco) were on hand, having already arrived in Miami as their teenaged daughter was winning the title in California.

It was a lot to adjust to, only four days after the unexpected triumph of her first win on the WTA.

"I hit 30 minutes before (Wednesday's postponement), and then 30 minutes today. So just an hour. Now, I know that it's pretty difficult to come into a new tournament after winning a really big tournament, because everyone has so many expectations," Andreescu said. "But I try not to focus on that, even though it's really difficult. And I think that's what happened today a bit in the first set."

Andreescu looked short on energy, understandably. While Begu was relatively cool and collected in the other chair, Andreescu was draping the ice towel around her neck, or across her upper legs. She sat on changeovers with another big bag of ice between her thighs. Occasionally, she poured some water over her head.

And Andreescu's game, usually full of variety, wasn't working.

Some of that was Begu, who she had beaten in the first round of that Indian Wells run. The veteran Romanian played much better this time, until it came time to close out Andreescu.

After Begu broke her serve for the second time to take a 4-1 lead in the second set, a tearful Andreescu looked for a little inspiration with an on-court consult from coach Sylvain Bruneau.

"I'm not feeling anything out there. Every time I try to do the right thing, it never goes my way," said Andreescu. "I'm getting so mad at myself. I'm, like, so irritated."

Bruneau told her to mix it up more. He told her she wasn't far away. After that consultation Andreescu got a second wind just as her opponent got tight.

"He obviously helped me, as he always does. I fought as hard as I could, and I'm really proud of myself with how I dealt with everything," Andreescu said.

Begu served for the match at 5-2 in the second set, and squandered a match point. She served for it again at 5-4, gave Andreescu a couple of free points, and the Indian Wells champion found her wings again.

In the third set, the big question was whether or not Andreescu could just keep holding her own serve, after an early break.

It turns out she had enough in the tank, after 2 1/2 hours, to do even better than that.

She broke Begu's serve a second time for safety, and closed it out.

As with Begu, Kenin is a repeat opponent for Andreescu in her breakout season.

The 20-year-old American defeated Andreescu in the semifinals of the WTA tournament in Acapulco, Mexico, the week before Indian Wells.

She was, in fact, the last player to defeat Andreescu, and one of only three players to accomplish that feat during a 2019 season in which Andreescu is now 29-3.

Also on Thursday afternoon, Andreescu's fellow 18-year-old Canadian Felix Auger-Aliassime advanced to the second round with a 3-6, 6-1, 6-2 victory over Norwegian qualifier Casper Ruud.

"I feel like since the beginning of the season, I've had some good starts to matches. Normally I start serving well. But not today," Auger-Aliassime said. "The wind, the noise from the next court, both of us had trouble winning our serve at start. But I stayed calm, tried to find solutions, and I found my rhythm and my zones as the match went on."

Note to readers: This is a corrected story. An incorrect name for Casper Ruud was used in a previous version