United’s forward line were full of running, movement and one-touch passing, harrying Celtic’s defence into rushed clearances and desperate blocks.
Darren Fletcher had a glorious opportunity to double United’s advantage on the stroke of half-time but fired over from eight yards after controlling Rooney’s cross.
But it didn’t take long after the break for Berbatov to score his – and United’s – second goal with another predatory finish.
Anderson was fouled by Scott Brown 25 yards out, Artur Boruc could only parry Ronaldo’s resulting free-kick and Berbatov was left with the simple task of slotting home the rebound.
It was the Bulgarian’s third goal in two games and fourth in two Champions League outings. And to think that people were doubting him a month ago.
Rooney thought he’d got on the scoresheet soon after but was flagged offside - although replays showed he wasn't - as he ran onto Fletcher’s neat slide-rule pass.
Berbatov looked disappointed when he was called off on the hour mark, but the two-goal forward left the field to a standing ovation, with Neville also replaced by Wes Brown.
Berbatov’s replacement Carlos Tevez flashed narrowly wide minutes later but United soon had a third as Gordon Strachan's men were opened up once more.
The move started with van der Sar’s throw to Fletcher, who sprayed the ball out wide to Tevez. The Argentine's simple ball across goal allowed Rooney to control, make room for himself and fire his fourth goal in four games from 18 yards.
Not even the most staunch of Celtic fans could deny the