World No 1 Novak Djokovic threw down the gauntlet to a resurgent Roger Federer on Saturday by challenging him to "keep up" as the Serb bids to repeat his landmark 2011.
Novak Djokovic and Roger Federer. Pic/Getty Images
Djokovic shrugged off the all-time grand slam champion's strong finish to last season culminating in victory at the ATP World Tour Finals.
The 24-year-old Djokovic went 70-6 last year and won 10 of 11 finals including three grand slams, starting with his demolition of Andy Murray at the Australian Open in January.
And Djokovic, speaking before beginning his title defence in Melbourne, warned he was primed to repeat his golden season, despite Federer's late-year hot streak.
"Well, he finished off the season best from all the other players. He had over 15 wins in a row. He definitely loves playing indoors.
He loves playing in the London event," Djokovic said. "But, you know, it's a whole new year. It's a whole new season. We're starting to play outdoors. We'll see if everybody can keep up."