By Simon Cambers

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 Andrey Golubev but slowly wore down the 23-year-old to clinch a 4-6 6-3 6-1 victory.

"Obviously I don't want to find any excuses but we got here just two days ago and it's really hard to get used to the time change and the conditions here," Djokovic said.

"He was stepping in and was definitely the best player in the first set, but I found my pace and I was happy the way I finished off."

Djokovic looked like he was suffering from jet-lag in the early stages and Golubev, who began 2010 down at world number 133, took advantage.

But Djokovic, who last month helped his country win the Davis Cup for the first time, broke in the opening game of the second set and with his confidence restored he dropped just four more games.

Ivanovic, who climbed back to 17th in the rankings after free-falling in the first half of 2010, overcame some early-season nerves to see off Shvedova.

The former French Open champion then lifted her game in the second set to cruise to a morale-boosting victory.

"I think we were both really nervous and it was so hard to hold our serves at first," Ivanovic said. "I started to serve a little bit better in the tiebreak and then in the second set."

On Monday, in Group B action, Britain play Italy while France meet the U.S. On Tuesday, Serbia play their next Group A opponents, Australia.

(Editing by Dave Thompson)