PERTH (Reuters) - Novak Djokovic kick-started his 2011 campaign with a well-earned victory on Sunday as top seeds Serbia whitewashed Kazakhstan 3-0 in their opening Group A match at the Hopman Cup mixed team event. The world number three dropped the first set to the hard-hitting Andrev Golubev but slowly wore down the 23-year-old to clinch a 4-6 6-3 6-1 victory.