Rory McIlroy has had a few pretty good rounds in his career, so when the four-time major champion applauds Australian Open winner Jordan Spieth for firing an 8-under 63 in Sunday’s final round, the golf world takes notice.

You could give me another 100 rounds today at The Australian and I wouldn't sniff 63.... Well done @JordanSpieth very impressive! — Rory Mcilroy (@McIlroyRory) November 30, 2014

Spieth ran away from hometown favorite Adam Scott and McIlroy, the world No. 1 who played himself out of contention with a 76 Saturday, with a flawless game in blustery conditions that flummoxed many in the field at Sydney’s Australian Golf Club. In addition to being only one of eight contestants to break 70 in the finale, Spieth was one of eight to close in the red when he finished at 13-under.

"With these conditions the golf course is very difficult," Spieth said after his convincing victory. "It's definitely the best round I have ever played and the best win I have ever had."

The winner of the 2013 John Deere Classic on the PGA Tour, Spieth lapped runner-up Rod Pampling by six strokes and left Scott and McIlroy in his dust by nine and 15 shots, respectively. McIlroy, who won the 2011 U.S. Open and 2012 PGA by eight shots each, fell apart in the third round when a triple-bogey seven on the ninth and a double on the par-4 10th ended the defense of his 2013 title.

Spieth, who will reportedly move from No. 14 to 11th in the world rankings come Monday, will tee it up next week at Tiger Woods’ Hero World Challenge.