Diego Costa struck to deny Manchester United a first victory over Chelsea in 10 attempts.
Jesse Lingard's goal looked to have earned United a first win over Chelsea since October 2012, but Costa capitalised on Daley Blind's stoppage-time error to tuck in his seventh goal in nine games in the 1-1 Premier League draw.
The result extended the Blues' current unbeaten run to 11 games. Guus Hiddink remains undefeated as Chelsea caretaker boss, with the Premier League champions' most recent loss at Leicester under Jose Mourinho on December 14.
Mourinho has been repeatedly linked with succeeding Louis van Gaal at Manchester United and the visitors' Dutch boss would have been disappointed to see the lead lost.
United had been on course to move within 10 points of leaders Leicester and five points of second-placed Manchester City, but now Van Gaal's men are 12 and seven points behind those two, respectively.
Chelsea - and John Terry, in particular - felt they should have been ahead before Lingard's goal.
The Chelsea captain believed Daley Blind handled his shot in the box late in the first half and that the Blues should have had a penalty. Referee Michael Oliver disagreed.
The Blues, who lost Kurt Zouma to what appeared to be a serious knee injury, had opportunities, only for David de Gea to keep out Branislav Ivanovic's volley and Cesc Fabregas' near-post effort before Costa's leveller.
Terry was making his first appearance at Stamford Bridge since last Sunday's declaration from the skipper that Chelsea would not be renewing his contract when it expires at the end of the season.
The Blues maintain the possibility remains an offer will be tabled to the skipper, but, in a show of solidarity from the supporters, banners were peeled back from The Shed and Matthew Harding Ends, with one remaining. "JT Captain, Leader, Legend" it read.
Owner Roman Abramovich was present to hear the pro-Terry chants of "Sign him up". Terry thanked the fans at the final whistle.
Both sides were unchanged from their midweek fixtures and United, buoyed by their 3-0 defeat of Stoke, hemmed Chelsea back for much of the opening 25 minutes.
A Michael Carrick shot extended Thibaut Courtois before Anthony Martial cut in from the left, shot viciously across goal, only for the goalkeeper to save smartly.
Chelsea belatedly responded, with a Costa header deflected narrowly wide and a Nemanja Matic header saved by De Gea.
Oscar next played in Costa, who shot wide across goal, before the playmaker blasted off target.
Willian then left Cameron Borthwick-Jackson on his bottom on the right, but his cross was out of Oscar's reach.
United had chances too. Marouane Fellaini headed Blind's corner just wide and Matteo Darmian's cross was tantalisingly out of Rooney's reach.
Chelsea's handball appeal was dismissed and United resumed the stronger.
After Wayne Rooney forced a save from Courtois, Martial ran at Ivanovic and fired just wide.
Courtois saved from Lingard, then Rooney, before Chelsea suffered a double blow.
Zouma was forced off after landing awkwardly and then Lingard scored.
Borthwick-Jackson crossed from the left, Rooney laid the ball off and Lingard held off Azpilicueta to shoot high into the net.
De Gea denied Ivanovic and Fabregas before Blind was caught ball-watching and slipped as he tried to change direction, allowing Costa in.
United withstood a late bombardment from Chelsea, but it would have been of little consolation after they missed out on victory.
TWEET OF THE MATCH:
"Watching Fellaini do battle against Matic is like watching Jurassic Park! #CFCvMUFC." - Former Wales and Cardiff defender Daniel Gabbidon ?@Gabbidon35
Thibaut Courtois: 7
Branislav Ivanovic: 7
Cesar Azpilicueta: 6
Kurt Zouma: 7
John Terry: 7
Nemanja Matic: 6
John Obi Mikel: 6
Diego Costa: 7
Cesc Fabregas: 8
Eden Hazard (for Oscar, 55 minutes): 6
Gary Cahill (for Zouma, 59): 6
Pedro (for Matic, 67): 6
David de Gea: 8/10
Matteo Darmian: 8
Cameron Borthwick-Jackson: 5
Chris Smalling: 6
Daley Blind: 6
Michael Carrick: 8
Marouane Fellaini: 5
Jesse Lingard: 8
Anthony Martial: 7
Wayne Rooney: 6
Juan Mata: 6
Morgan Schneiderlin (for Fellaini, 79): 5
Memphis Depay (for Lingard, 87): 5
Ander Herrera (for Mata, 90): 5
David de Gea. Made a number of fine saves to keep Chelsea out, until Diego Costa breached the defence late on.
MOMENT OF THE MATCH
Not one moment, but a series of moments relating to John Terry, who is out of contract at the end of the season. The usual fan banners at either end of the ground were peeled back so one remained. It read: "JT Captain, Leader, Legend". "Sign him up," the fans sang. And the captain thanked the supporters at the end.
VIEW FROM THE BENCH
Guus Hiddink named the same starting XI for three successive Premier League games, with Eden Hazard again kept in reserve. United were also unchanged following their convincing win over Stoke. Hazard was thrown into the fray with 35 minutes remaining and Pedro followed after the enforced replacement of Kurt Zouma by Gary Cahill. Neither Hazard nor Pedro could inspire Chelsea, but Costa capitalised on a mistake. United looked the more dangerous, with Louis van Gaal opting for directness, but the visitors could not find a second and were punished.
MOAN OF THE MATCH
Another penalty debate. Does there need to be a clarification over when handball is handball? When Daley Blind's arm was in a natural position, tucked into his body, and was struck at point-blank range there should surely not even be a debate.
WHO'S UP NEXT
Chelsea v Newcastle (Barclays Premier League, Saturday, February 13)
Sunderland v Manchester United (Barclays Premier League, Saturday, February 13)
When questioned about his future at the club, Blues skipper Terry told Sky Sports 1: "It's a difficult one. The club's the most important thing.
"There's no communication between myself and the club at the minute and I said what I had to say and that's how it was. But more importantly we need to start winning matches and get up the table where we should be.
"We're disappointed to be where we are in the league but the fans have been brilliant and stuck with us thick and thin."
Regarding the penalty appeal in the first half, he added: "It was going in I think. He's put his hands up...they're difficult ones for the referee, inside the box it's going in, it's got to be a penalty for me."
"It's not a bad result but we need to start winning."
Terry also reserved praise for the club's fans, saying: "(The atmosphere was) incredible, they're the best fans in the world. What they've done and given for me as a young 14 and 17-year-old boy... I'll never forget. The memories will live with me forever."
After the draw with his former club, United's man of the match Mata said: "We played very good football to be honest. Coming here to Stamford Bridge and playing the football that we played in the first 30 minutes and in the second half as well.
"We had it so close but in the end Chelsea are always trying to score and create chances and they scored a late goal and we didn't have any time to try to come back.
"It's always special to play here."
Goalscorer Lingard added: "I think we played the majority of the game well. After conceding late on it felt like a defeat but we have to move onto the next game now."