Didier Drogba fed Kalou at the far post to poke it into the unguarded net in the 89th minute.
After Sandro's first goal for Tottenham, Chelsea was given a route back into the game on the stroke of halftime, when Frank Lampard's fierce, dipping 30-meter (yard) strike squirmed through Gomes' arms and legs.
As Gomes desperately stretched back, he managed to just stop the ball creeping completely over the line, but referee Andre Marriner and assistant Mike Cairns ruled the goal should stand.
Chelsea is three points behind Manchester United, which is still to play at Arsenal on Sunday before hosting Carlo Ancelotti's second-place side a week later.
Lampard said he felt he deserved such a favorable decision after being denied a clear goal for England at the 2010 World Cup, when the ball from his shot clearly crossed the line in the last-16 match that Germany went on to win.
The embarrassment at FIFA led to president Sepp Blatter reviving investigations into goalline technology, although football's lawmaking body is yet to find a high-tech aid that rules on disputed goals with perfect accuracy and speed.
Tottenham's failure to win at Stamford Bridge for the first time since 1990 is a blow to the north London club's hopes of qualifying for the Champions League for a second successive season.
Harry Redknapp's side is four points behind Manchester City in the fourth and final Champions League spot having played an extra game, although the two sides must still meet.
Before the latest botched piece of goalkeeping from Gomes, the erratic Brazilian had been frustrating Chelsea with a series of fine saves.
A powerful, swerving free kick from Drogba look destined for the top corner before the slightest of touches from Gomes' right hand pushed over.
A low save kept out Florent Malouda's effort and Michael Essien's header was tipped over, but all that fine work was underdone on the stroke of halftime.
After weathering early pressure, Tottenham took a surprise 19th-minute lead when Rafael van der Vaart flicked a throw-in over to Sandro to blast home his first goal for the club in his debut season.
Tottenham, though, couldn't build on the goal as Chelsea's luck turned, with the rejuvenated side winning for the eighth time in its last nine matches.
The transformation has been despite — rather than due to — the 50 million-pound (then $81 million) arrival of Fernando Torres in January.
Some of the pressure on the Spain striker was relieved by his first Chelsea goal in last Saturday's win over West Ham United.
The reward was a starting spot against Tottenham, but the closest he came to finding the net was the side-netting after 10 minutes, and he was hauled off in the 62nd.
His best contribution was being replaced by Kalou, who went on to deliver the three points.
Elsewhere Saturday, Blackburn scored their first victory in three months with a 1-0 win over Bolton that eased the club's relegation fears.
Rovers' Swedish international defender Martin Olsson scored the decisive goal at Ewood Park after 20 minutes, lashing in a low shot from 20 yards to beat the outstretched hand of Bolton goalkeeper Adam Bogdan.
In other games, Wigan were denied a priceless victory against Everton, who came from behind to secure a 1-1 draw at the DW Stadium.
Charles N'Zogbia fired Wigan ahead on 21 minutes, curling his shot into the top corner from the from the right of the penalty area.
Everton squandered a chance to equalize toward the end of the half however, when Mikel Arteta missed a penalty but made amends in the second half when Leighton Baines levelled from the spot on 78 minutes.
Blackpool's hopes of Premier League survival remain on a knife-edge after a gritty 0-0 draw with Stoke at Bloomfield Road.
The hard-earned point left Ian Holloway's men hovering just above the relegation zone, ahead of 18th placed Wigan on goal difference.
Fulham maintained their recent run of good form at Sunderland, downing the Black Cats 3-0.
The Cottagers went ahead through loan signing Gael Kakuta before Welsh international Simon Davies scored twice in the second half.
Ten-man West Brom came from behind to take the honors in their Midlands derby against Aston Villa, winning 2-1 at the Hawthorns, goals from Peter Odemwingie and Youssouf Mulumbu giving the Baggies the win after Villa had taken the lead through an Abdoulaye Meite own goal.
