The first of seven phases, Friday's vote covered 166 million voters in 102 constituencies across 21 states and territories
Ancelotti’s spluttering side were heading for a fifth defeat in nine games after Roman Pavlyuchenko’s first-half strike put Spurs in front.
But Gomes gifted Chelsea an equaliser with 20 minutes left when he allowed Drogba’s shot to escape his grasp and loop into the net.
Drogba had a golden opportunity to steal the points for Chelsea when Gomes conceded a stoppage time penalty, but the Ivory Coast striker saw his spot-kick brilliantly saved by the Brazilian.
Chelsea were well below their best once again and Ancelotti, under increasing pressure in recent weeks, will be cursing Drogba’s miss, which leaves the Blues one point behind Arsenal ahead of the leaders’ trip to Manchester United on Monday.
Several previous Chelsea managers were sacked for less than the team’s miserable run of just two wins in their last eight games, so it was a brave move by Ancelotti to leave Drogba on the bench.
Although Drogba has struggled to recapture the form that made him the Premier League’s top scorer last season, he remains Chelsea’s most potent attacking option and his side were toothless without him in the first half.
If Drogba’s absence played a part in Chelsea’s slow start, they were hindered even more by a continued lack of security at the back.
Once the cornerstone of Chelsea’s success, Ancelotti’s defence now gifts chances with alarming regularity and Pavlyuchenko took full advantage to open the scoring in the 15th minute.
When Jermain Defoe cut infield and found Pavlyuchenko in the penalty area, Chelsea captain John Terry should have closed down the Russian striker. Instead he and John Obi Mikel sat back and allowed Pavlyuchenko to drill a low shot past Cech at his near-post.
Replays showed Defoe may have been just offside before crossing, but that was no excuse for Chelsea’s poor defending.
Over 25 minutes passed before Gomes was seriously tested when Salomon Kalou’s header from Nicolas Anelka’s cross forced the Brazilian into action.
Another Chelsea defensive lapse should have been punished with a second goal for Pavlyuchenko, but he couldn’t keep his shot on target after running unmarked onto Gareth Bale’s free-kick.
Only Florent Malouda was providing a sustained threat for Chelsea and he set up two chances for Kalou, who glanced his first header wide and then skied the next headed effort well over.
Chelsea had plenty of possession as the half wore on but there was no cutting edge and it was no surprise when Ancelotti sent on Drogba for Mikel at the interval.
Drogba’s arrival almost paid immediate dividends as his long-range shot was pushed away for a corner by Gomes, who had to make another acrobatic stop moments later to prevent Wilson Palacios heading a Drogba cross into his own net.
With Drogba up front, Chelsea at last had some focus to their attacks. They lacked composure at times, but that didn’t matter as Gomes gifted Chelsea their equaliser in the 70th minute.
Drogba showed tremendous strength and skill to control a hopeful punt and flick it past Michael Dawson. However, his shot was straight at Gomes and should have been saved. Instead the Brazilian’s weak attempted stop only managed to push the ball into his net to the delight of Ancelotti and his players.
Ancelotti sent on Frank Lampard for his first appearance in over three months with 12 minutes remaining and Chelsea pressed forward for a winner.
It should have arrived in stoppage time when Gomes conceded a penalty by barging into Ramires, but the goalkeeper redeemed himself as he dived to keep out Drogba’s spot-kick.
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