Tottenham had struggled to find their best form following their Carling Cup win over Chelsea, but looked to be back to their best at White Hart Lane.
Berbatov proved the difference once again as his two early headers stunned the Hammers players before substitutes Gilberto and Darren Bent sealed all three points for Juande Ramos's side.
West Ham's cause was not helped when Luis Boa Morte was shown a red card for two bookable offences on the stroke of half-time.
Alan Curbishley's team suffered their third 4-0 defeat on the spin and their chances of qualifying for European football have now all but faded away.
However, the visitors could have opened the scoring after four minutes when Freddie Ljungberg's shot was fumbled by Paul Robinson in the Tottenham goal. Boa Morte eventually got to the rebound but saw his shot deflected over the bar.
Tottenham made them pay when they broke the deadlock on eight minutes. Tom Huddlestone's free-kick picked out Berbatov who rose above Anton Ferdinand to head the ball past Robert Green and into the corner of the net.
Things got even better for the home side when they added a second just three minutes later.
It was a carbon-copy of the first goal as Huddlestone's free-kick once again picked out Berbatov who found himself free in the box and the Bulgarian directed his header past the West Ham keeper.
The Hammers' miserable first half was compounded when Boa Morte was dismissed for his second bookable offence.
Referee Chris Foy had no hesitation in brandishing the red card following Boa Morte's lunging challenge on Aaron Lennon.
Lennon came close to getting on the scoresheet when he saw his shot cleared off the line by Ferdinand.
Substitute Gilberto added a third goal for Tottenham on 85 minutes. Pascal Chimbonda played the ball into the midfielder and the Brazilian fired a left-foot shot past Green.
Darren Bent scored a fourth goal in stoppage time when his downward header beat Green to complete the rout.