Aryna Sabalenka believes her first-round victory over Sloane Stephens at the Australian Open demonstrated her maturity over the last few years.

Sabalenka, the two-time reigning champion at Melbourne Park, kickstarted her bid for a three-peat with a 6-3 6-2 win over 2017 US Open winner Stephens on Sunday.

The Belarusian has now won her last 17 first-round matches at grand slams, last falling at the first hurdle at a major against Carla Suarez Navarro at the 2020 Australian Open.

She has also won her last 15 main-draw matches at the Australian Open, the longest winning streak at the Melbourne slam since Victoria Azarenka reeled off 18 straight victories between 2012 and 2014.

Her victory was less routine than it seemed, though, as a first-set wobble from Sabalenka allowed Stephens to pick up consecutive breaks and make the opener competitive.

However, Sabalenka recovered her composure in a way she feels may not always have been possible in the past.

"I think it's a big difference if I compare myself to even three years ago," she said when asked about her mentality in her post-match press conference.

"In that moment, I would get frustrated and probably would lose the first set. I'm not sure if I would be able to win the match. That's what I remember.

"I'm really glad that I improved my mental toughness, let's say. I'm able to stay focused, no matter what the score or what the situation is. I'm focusing on the game, on the point. I'm focusing point by point."

Sabalenka is hoping to become the first woman to win three straight Australian Open crowns since Martina Hingis between 1997 and 1999, but she thinks ignoring talk of a three-peat will aid her title tilt.

"I think the biggest lesson I learned last year is just not focusing on defending the title or having the opportunity to put your name in history or whatever," she added.

"I think the key is just to keep focusing on yourself and trying your best and see what happens after the tournament.

"Let's talk about that after I finish the tournament, hopefully with a three-peat, then I can tell you which one was the toughest one!"