Jason Day made his return to No. 1 in the world fell even sweeter Sunday by winning the Dell Match Play.

Day outlasted Rory McIlroy in an epic battle in the semifinals by making a 12-foot par putt on the final hole. The championship match against Louis Oosthuizen turned into a victory lap at Austin Country Club.

Day pulled ahead with a 10-foot birdie putt on the fourth hole, stretched his lead to 3 up at the turn and was relentless the rest of the way. He closed out Oosthuizen on the 14th hole to win, 5 and 4.

It was the biggest rout in a title match since Tiger Woods beat Stewart Cink, 8 and 7, in 2008.

Day now has won six of his last 13 starts.