Jordan Spieth, who created a buzz when at 19 when he became the youngest player to win a PGA Tour event in 82 years, is playing the best golf of his 21-year-old life and taking aim at the world No.1-ranked Rory McIlroy.

Jordan Spieth, who created a buzz when at 19 when he became the youngest player to win a PGA Tour event in 82 years, is playing the best golf of his 21-year-old life and taking aim at the world No.1-ranked Rory McIlroy.

Spieth followed up a six-stroke victory at last week's Australian Open with a 10-shot romp at the Hero World Challenge at Isleworth, Windermere, Florida, on Sunday to finish his year inside the world top 10 at No.9.

Had it not been for a rare four-putt on the 17th hole at Dunlop Phoenix in Japan, it might have been a hat-trick for the Texan, who finished one shot behind there.

"Right now, it [his game] is at its highest level it's ever been," said Spieth after his final-round 66 for 26-under-par 262 and a 10-stroke victory over the Swede Henrik Stenson. "This is the best I've ever played, which is what I said in a media centre in Sydney last week. I played better this week."

Spieth made a huge splash when he won the 2013 John Deere Classic in a play-off. Now he has designs on winning majors and climbing to the top of the world rankings.

"In order to take it to the next level and try and win majors, I got to look to Rory," Spieth said of the 25-year-old Northern Irishman, who won the last two majors ?? the Open Championship and the US PGA Championship ?? to take his haul to four.

"He's the youngest guy: the one with the most success. He's No.1 in the world and setting the bar. He's the one we're all chasing," added Spieth, who held the Masters lead during the final round before finishing joint second.

"I think I did a good job of starting that chase these last couple of weeks. That's only really the beginning of what needs to happen for the ultimate goal, which is to overtake him."