Day, who won the tournament back in 2014 and has been confirmed as the top-ranked men’s player after American Jordan Spieth was knocked out at the last 16 stage, produced a commanding performance on his way to beating Oosthuizen, winner of The Open in 2010, 5&4.

The 28-year-old, who has enjoyed a superb start to the year, including lifting the Arnold Palmer Invitational trophy earlier this month, accounted for world number three and four-time major winner Rory McIlroy in the semi-final.

The eagerly-anticipated contest between Day and McIlroy lived up to expectations and was a hard-fought encounter, with the Australian’s putt on the 13th proving crucial in a one-up victory.

Oosthuizen reached the final of the competition in Texas by ousting surprise package Rafael Cabrera Bello of Spain, seeded 52nd, by sealing a 4&3 win.

The Spaniard was able to finish the tournament on a high, however, as he claimed a shock 3&2 triumph over McIlroy in the third-place play-off.

But the day once again belonged to the Australian, whose back-to-back victories have come at a vital time with the first major of the season, The Masters at Augusta National, due to begin on April 7.

Oosthuzien had started the brighter of the two players by winning the opening hole but it was a fleeting moment of joy for the South African as Day began to take control.

He led by three going into the back nine and secured victory by taking the 13th and 14th holes.

“I'm very, very thrilled,” Day said.

“It's been a memorable week, not only to win the Dell Match Play Championship but also to get back to number one in the world.

“It would be great to win Augusta but I’ve got to make sure I get in and do the little things that count towards the big picture.

“That’s my preparation in getting ready for that week.

“Rest and recovery next week is huge for me, because it has been a long week and a long two weeks.

“I will get down there this Thursday and try and do the same old things and hopefully I can pull out a win.”