The Bulgarian marksman headed Alex Ferguson's unbeaten table toppers in front after five minutes and struck again with a deflected effort after the break as United moved to 37 points from 17 games at the start of a hectic holiday program.
Berbatov now leads the league's scoring charts with 13 goals, one more than former United striker Carlos Tevez who bagged two for Manchester City as they went second with 35 points from 19 games thanks to a 3-1 victory at Newcastle United.
Arsenal can move back above City on goal difference with a win over fourth-placed Chelsea on Monday.
Bolton Wanderers are up to fifth after a 2-0 home triumph over West Bromwich Albion. Stoke City are eighth following a 2-0 victory at Blackburn Rovers.
Carlton Cole was another striker in form, grabbing two goals for West Ham United as they won 3-1 at Fulham to climb off the bottom of the table, above Wolverhampton Wanderers who were beaten 2-1 at home by fellow strugglers Wigan Athletic.
The snow and ice that has played havoc with Britain's sporting calendar in recent weeks meant Blackpool's pitch was unfit for their home match against Liverpool.
Everton's Goodison Park stadium was hit by frozen water pipes, meaning their game against Birmingham City was also postponed.
There was nothing wrong with United's circulation, however, as they opened imperiously against Sunderland.
Two weeks after beating Arsenal 1-0 when Berbatov failed to make the starting line-up, he returned with a typically stylish performance.
As United pinged the ball around with relish he gobbled up his first chance when Ryan Giggs played in Wayne Rooney and his perfect cross was headed in by the Bulgarian.
United dominated without adding to their score and there was relief for the home fans when Berbatov's 57th-minute shot went in off Sunderland defender Anton Ferdinand.
"The first half was the highlight," said United manager Alex Ferguson, whose side visit Birmingham on Tuesday. "Some of the football was fantastic and we could have scored four or five.
"We were pretty economical with our performance in the second half," he told Sky Sports News.
