MELBOURNE, , (Pakistan Point News - APP - 19th Jan, 2017 ) - Fallen Grand Slam king Novak Djokovic admitted opponents now believe he is more vulnerable following his stunning second-round exit from the Australian Open. The six-time winner and 12-time Grand Slam champion crashed out to unheralded Denis Istomin in five sets on Thursday in the world number two's earliest exit from a major since Wimbledon 2008. Djokovic's stuttering start to the new season comes after he lost the world number one ranking he had held for 122 weeks from 2014 to Britain's Andy Murray in November.
He also relinquished his Wimbledon and US Open titles and was eliminated in the first round of the Rio Olympics by eventual champion Juan Martin Del Potro of Argentina. The 7-6 (10/8), 5-7, 2-6, 7-6 (7/5), 6-4 loss to the 117th-ranked Istomin will only raise more questions about Djokovic's ability to stay at the top after dominating tennis for the last six years. Asked if opponents have started to believe more over the last six months that he was beatable, Djokovic said: "Sure. They wouldn't be playing against me or any other opponent or any other tournament, for that matter, if they don't believe that they can win.