Keys uses friendly fire to claim Adelaide International

But the world No.20, despite strapping on her left thigh, finished with a flourish to claim her ninth career singles title.

Madison Keys served her way to a second singles title at the Adelaide International. (Matt Turner/AAP PHOTOS)

Keys, who also won the Adelaide trophy in 2020, was 0-3 down in the second set when she sought treatment.

"It was just one of those things that kind of appeared and luckily, with the magic of tape, things felt a little bit better and I was able to get through the match," Keys said.

"Once the immediate kind of panic of 'oh no, something is happening' (ended), I think I finally relaxed and was able to refocus on the match.

"And in some ways it just made me go for it a little bit more and go after things a little bit quicker - luckily they were going in.

"In some ways it helped me be a little bit more aggressive."

Keys won 10 of 14 games after her medical time-out and her overt aggression paid off: she struck 40 winners compared with Pegula's 10 in the match.

Good friends Madison Keys (left) and Jessica Pegula played a three-set final in Adelaide. (Matt Turner/AAP PHOTOS)

"When you play Jess, you don't really want to give her a lot of balls to get a lot of rhythm because then all of a sudden you're running and she's just zinging things by you," Keys said. 

"It's one of those matches where you have to try to take the initiative as soon as you get it."

Keys and world No.7 Pegula, 30, have formed a close bond in their years on tour and will soon catch the same flight to Melbourne for the Australian Open starting on Sunday.

The last time Keys won in Adelaide, she reached the semi-finals at the Open when beaten by eventual champion Ash Barty 6-1 6-3.

"It's just putting myself out there and continuing to give myself the opportunity to play good tennis, and a lot of times good things follow," Keys said.

"Luckily, Ash Barty is not here to embarrass me any more."