Defoe, who is still booed by Charlton fans following his controversial move from The Valley to West Ham as a youngster, was the difference between the two sides at White Hart Lane.
The England striker has failed to command a regular first-team place in the last two months, but was back to his best to help Spurs get back on the winning trail.
With north London rivals Arsenal winning at Birmingham just 24 hours earlier, the pressure was on Tottenham to deliver and they didn't let anyone down with a first-class performance to see off a poor Charlton outfit.
Defoe scored in each half and was assisted by Jermaine Jenas who ensured a consolation strike by Jerome Thomas would not be enough to see Tottenham pick up all three points.
Tottenham got off to a bright start and almost broke the deadlock after eight minutes when Defoe's deflected shot produced a fine save from Thomas Myhre in the Charlton goal.
The England striker was determined to get back among the goals and almost got on the scoresheet in spectacular fashion just 60 seconds later when his attempted lob from the edge of the box flew just over the bar.
Defoe did not have to wait much too much longer before scoring against his former club.
Jenas' ball picked out Defoe on 14 minutes who turned Jon Fortune inside the box before his deflected shot flew past Myhre into the top left-hand corner.
It was Tottenham's first goal in 291 minutes of play and a much-needed boost to Martin Jol's side.
Charlton midfielder Bryan Hughes was lucky to stay on the pitch on the half-hour mark after he brought down Paul Stalteri on the edge of the box when the Canadian defender had a clear run at goal.
But Tottenham got their just rewards when they added a second on 42 minutes. Robbie Keane's ball picked out Jenas inside the box who got the better of Chris Powell before slotting the ball past Myhre into the bottom left-hand corner.
Marcus Bent could have pulled Charlton back into the game on the stroke of half-time when his thunderous 25-yard drive cannoned back off the crossbar.
And how Charlton were made to pay as Defoe added his second of the game and Tottenham's third just 46 seconds into the second half.
Substitute Tom Huddlestone won the ball off Radostin Kishishev in the heart of the midfield before releasing the ball into the path of Defoe.
Defoe showed his goalscoring instincts once again when he made no mistake striking the ball past Myhre to remind the Tottenham management why he should be a regular in the starting line-up.
Keane could have made it four for the home side on 63 minutes when he burst into the box and took the ball around Myhre. But his shot was cleared off the line by Charlton defender Hermann Hreidarsson.
Defoe was denied the chance to score his hat-trick on 65 minutes when his shot inside the box was superbly saved by Myhre.
Charlton were handed a glimmer of hope on 70 minutes when substitute Thomas beat Stalteri on the edge of the box and fired a low drive which sailed past Paul Robinson into the bottom right-hand corner of the Spurs goal.
And Hreidarsson could have made a real game of it on 88 minutes when his powerful header produced a stunning save from Robinson diving away to his left.
But it all proved in vain as Tottenham kept the pressure on Liverpool in third position and showed they will be genuine contenders for a Champions League spot.