Lleyton Hewitt upsets Roger Federer

Hewitt raced through the first set and then held off a comeback from the world number six to win 6-1, 4-6, 6-3 in two hours and seven minutes.

It was Hewitt's 29th title on the ATP tour but his first since 2010, when he also beat Federer in the final at Halle.

Hewitt has been plagued by injury in recent years and underwent surgery in 2010, 2011 and 2012 to fix various hip and foot problems.

"I think the most pleasing thing is what I've had to come through and the tough times in terms of surgery," the former Wimbledon and US Open champion said.

"Before the last surgery I made no secret (that) there were no guarantees I would be able to play again at all.

"There were still times when I came back from that surgery and played that Wimbledon straight after it, and I was still doubting whether I was ever going to be pain-free again.

"For me that's the most pleasing thing."

Hewitt, the world number 60, is projected to rise to 43 in the rankings as a result of the win, and will be one of the most dangerous floaters when the Australian Open draw is made on January 10.

Federer started the final poorly and made a staggering 22 unforced errors in the first set, perhaps showing the effects of playing both singles and doubles in the heat and humidity of a Brisbane summer.

However, Federer denied the high workload was to blame for his performance despite looking fatigued at times.

"I feel actually pretty good considering playing five sets yesterday and coming out and playing another three-setter today, (considering) the warmer weather the last couple of days in particular," he said.

The Swiss great had not lost his serve all week, but he appeared sluggish from the beginning and was broken to love in the first game.

"I really was struggling with all sorts of rhythm," Federer said.

"I wouldn't say I was serving poorly, but it was just a tough set for me. I was put on the back foot very often."

He managed to stop the rot on his next serve but Hewitt was soon back in control, breaking Federer twice more to take the first set in only 27 minutes.

Hewitt lost only one point on serve in the first set as Federer imploded, stunning the sellout crowd in the Pat Rafter Arena.

The second set started much the same way, with Hewitt holding easily and Federer struggling.

But the top seed gradually worked his way into form, halving his error rate and beginning to pressure the Australian.

He had the chance to break Hewitt in the fifth game but couldn't convert. However he struck immediately to break the Australian's next serve, then served three aces on his way to levelling the match.

Hewitt struggled to hold serve at the start of the third but surprisingly it was Federer who cracked first, dropping serve in the fourth game when a tired-looking forehand sailed long on break point.

The Australian then held serve easily to jump out to a 4-1 lead in the decider, and maintained the advantage to win the title.

"For the first set I was seeing the ball like a football -- it didn't really matter where he served, I was on it. I felt great out there," Hewitt said.

"As the match went on, I think I started getting a little more sluggish just after, obviously backing up from yesterday (when he beat Kei Nishikori in three sets)."

Hewitt said he was heading to the Australian Open full of confidence.

"I'll go out there and I'll compete exactly the same as I've competed here this week," he said.