Mexico City - Australia's Adam Scott carries an extra boost of confidence into this week's WGC Mexico Championship after winning his second title in three months last weekend at Riviera.

The 39-year-old captured the Tiger Woods-hosted Genesis Invitational having taken the Australian PGA Championship in December, giving the 2013 Masters champion an extra spring in his step this week at Club de Golf Chapultepec near Mexico City.

"It's very satisfying. Any time you win it's incredibly good for your confidence," Scott said.

"I felt that at the end of last year. I won the Australian PGA in December, and even in a funny way, just hitting a few balls on the range, I felt more confident than I did even hitting balls on the range Sunday in Riviera.

"It just gives you that little bit more self-belief in all the things that you need to do, and even the way I struck the ball showed there was a lot of confidence and self-belief standing over the ball to swing the club.

"It's funny, it's kind of immeasurable, and it's hard to fake what that win can give to you. It does mean a lot."

It was seventh-ranked Scott's first US win since the 2016 WGC event at Doral, which moved to Mexico the following year.

US star Dustin Johnson has won two of the three WGC Mexico events contested at Chapultepec, near Mexico City, edging England's Tommy Fleetwood by a stroke in 2017 and defeating runner-up Rory McIlroy by five shots last year.

Fifth-ranked Johnson will play the first two days alongside Italy's Francesco Molinari and Mexico's Abraham Ancer while world number one McIlroy and Fleetwood will be joined by American Gary Woodland, the reigning US Open champion, when the event begins Thursday.

Scott will play the first two rounds alongside Spain's third-ranked Jon Rahm and Mexico's Carlos Ortiz, making his first career WGC start.

"As I've started playing better and better last year, to be the best player out here, you've got to play against the best, and that means coming to these events," Scott said.

"It was pretty easy to put this back in and also the Match Play back on the schedule for this year and at least give myself an idea of where my game is sitting against the best players in the world a little more often."

Scott plans a week off, then the Arnold Palmer Invitational at Bay Hill and the Players Championship, then a week off before and after the WGC Match Play ahead of the Masters in April.

"The Match Play has never been the first one on my schedule, but it's another opportunity for just me to see at least three competitive rounds of golf, where I'm at, what I need to work on, keep me competitively pretty fresh with a week off before the Masters," Scott said.

There have been three Aussie winners of PGA Tour events this year, including Scott, Marc Leishman at Torrey Pines and Cameron Smith at the Sony Open in Hawaii.

"I had watched Cam win in Hawaii while I was sitting on the couch and Leish winning in Torrey, and that was about the time when I was feeling like, 'OK, I need to get back out there and try and put my name on a trophy,'" Scott recalled.

"Those things happen. The Aussies are all pretty close and a little success from one can push us all a long way."