First half goals from Marouane Fellaini, Michael Carrick and Rooney effectively ended the EPL match as a contest, with the win leaving United in fourth spot, but only two points adrift of second-placed Manchester City. Tottenham is seventh, six points adrift of the top four.
Rooney's third after another piece of disastrous defending from the visitors led to an impromptu and topical goal celebration, which was certainly the main talking point.
A national newspaper had posted a video on on social media Sunday which appeared to show Rooney being felled by fellow EPL footballer and former United teammate Phil Bardsley as both donned boxing gloves for a "friendly" fight in his kitchen.
After he had converted following a mistake by Nabil Bentaleb, Rooney threw a few mock punches then keeled over backwards on to the Old Trafford turf.
Tottenham's players and fans were probably the only people not to see the funny side, but the joke was on them, having gone into the match seeking a third straight away win at United and five games unbeaten against the Red Devils.
From United first significant attack on nine minutes, an unmarked Fellaini was found by Carrick and the Belgian international beat Hugo Lloris with a low shot.
Fellaini caused chaos in the Tottenham defense for the second with Carrick left free to head home from distance.
Rooney's emphatic strike after Bentaleb gifted him possession, proved the icing on the cake.
The victory eases the pressure on manager Louis Van Gaal and his expensively assembled side after some lackluster recent performances and last Monday's disappointing FA Cup exit to Arsenal.
It meant Tottenham, off the back of two straight wins and with Harry Kane in top form, was favored going into the crucial match, but the young striker barely had a glimpse of goal, until having his side's first shot on target after fully 88 minutes as United dominated.
Chelsea held at home
Earlier, Chelsea extended its lead at the top of the EPL to six points but was held 1-1 at home to Southampton in another less than convincing performance from Jose Mourinho's team.
Off the back of a disappointing Champions League exit to Paris Saint Germain, Chelsea again struggled to find its best form at Stamford Bridge despite going in front from Diego Costa's 18th league goal.
Dusan Tasic equalized from the spot for the Saints after Nemanja Matic was adjudged to have fouled Sadio Mane, with Chelsea protests waved away.
Chelsea found Fraser Forster hard to beat and the visiting goalkeeper made fine saves from Oscar, Eden Hazard and Juan Cuadrado to deny the leaders three points.
However, it has a commanding lead plus a game in hand over chasing Manchester City, which lost 1-0 to Burnley Saturday, in a severe blow to hopes of retaining the title.
In Sunday's other EPL clash, Everton eased its relegation fears with a 3-0 win over Newcastle, who had Fabricio Coloccini sent off for a foul on Aaron Lennon, who is on loan at Goodison from Tottenham.
Bale double lifts Real
In La Liga, Gareth Bale snapped a recent lean spell of scoring form with both goals as Real Madrid beat Levante 2-0 in the Bernabeu.
The record signing struck first in the 17th minute when Cristiano Ronaldo's acrobatic effort was cleared off the line and the Welshman scored the rebound.
The same combination was at work for the second in the 40th minute with Ronaldo's strike helped into the visiting net by Bale.
Ronaldo might have added to the tally and missed several opportunities but Real was never threatened by Levante and eased to the three points.
It leaves them a point adrift of Barcelona ahead of next weekend's El Clasico, which could go a long way to determining the title race.