Tiemoue Bakayoko switched off for a split-second, lost his man and Saul Niguez cast a very different complexion across Chelsea’s European campaign.
The Niguez header, early in the second half, cost Antonio Conte’s team top spot in Group C and could have lingering repercussions.
The Premier League champions managed to equalise when former Manchester City defender Stefan Savic deflected a low drive by Eden Hazard into his own net – and there were chances to win the game.
Chelsea went level against Atletico Madrid when Eden Hazard’s shot was turned past Jan Oblak by team-mate Stefan Savic
The central defender tried to clear Hazard’s left-footed effort but could only watch as the ball went into the Atletico goal
Hazard was the quickest to turn away and celebrate after Savic’s mishap with 15 minutes left to play at Stamford Bridge
Saul Niguez’s header gave Atletico Madrid a chance of qualifying for the Champions League knockout stages
Chelsea goalkeeper Thibaut Courtois reacts after Tiemoue Bakayoko allowed Niguez to move into space before scoring
The Atletico Madrid winger celebrates scoring his first Champions League goal of the season
The 23-year-old went straight over to the Atletico Madrid fans who were housed in the bottom right of the Shed End
MATCH FACTS, RATINGS AND GROUP C TABLE
CHELSEA (3-5-2): Courtois 6; Azpilicueta 6.5, Christensen 6.5, Cahill 6; Moses 6.5, Fabregas 7, Kante 7, Bakayoko 5 (Pedro 64), Zappacosta 6; Morata 7 (Batshuayi 81), Hazard 7.
Goals: Savic OG 75
Booked: Zappacosta
Subs not used: Caballero, Rudiger, Alonso, Drinkwater.
Manager: Antonio Conte 6
ATLETICO MADRID (4-4-2): Oblak 7.5; Gimenez 6 (Vietto), Savic 6, Lucas 6, Luis 6; Partey 5, Gabi 6.5 (Correa), Ninguez 7, Koke 6.5; Torres 6.5 (Carrasco 57, 6), Griezmann 6.
Goals: Niguez 56
Booked: Lucas
Subs not used: Moya, Godin, Gameiro, Vrsaljko.
Manager: Diego Simeone 6
Referee: Danny Makkelie (NED) 6
Atletico Madrid went ahead when Saul Niguez scored with a header from close range – see more with our brilliant Match Zone
Atletico Madrid goalkeeper Jan Oblak produced a fine late save to thwart Alvaro Morata and WIllian sliced over when the goal was gaping.
Michy Batshuayi almost produced a stunning winner in the closing seconds and Hazard, inexplicably, drifted offside when he and Willian had the visitors stretched on another counter-attack.
So Bakayoko was not the sole culprit and yet his lapse in concentration will loom large at Monday’s draw in Switzerland.
Victory would have ensured Chelsea won in the group and the relative comfort of top-seeding when the ties are pulled out for the last-16.
Atletico Madrid manager Diego Simeone puts his hands to his head during a frustrating first half at Stamford Bridge
Atletico Madrid goalkeeper Jan Oblak makes a vital save after Chelsea’s Zappacosta nearly caught him out at the near post
Chelsea Tiemoue Bakayoko managed to work his way into the Atletico Madrid box but his left-footed shot was saved
Roma, who beat Qarabag in Italy, finish ahead of the Londoners by virtue of their head-to-head results.
Which means Chelsea will have only three options in the draw if all other English clubs win their groups.
These will include Paris Saint-Germain, Barcelona, Besiktas and possibly Sevilla, if they win Liverpool’s group.
Atletico go into the Europa League. They arrived knowing they would need a minor miracle to progress.
They were delayed by London traffic, were late to hand in the team line-up but they opened with purpose, determined, at least to try to fulfil their side of the bargain.
Fernando Torres, on his first return to Stamford Bridge, where he endured a difficult time in Chelsea blue unleashed the first shot of the game, which was deflected over. It must have been a familiar feeling.
There was a break in play when Chelsea defender Gary Cahill collided with Atletico Madrid forward Antoine Griezmann
Griezmann and Atletico Madrid team-mate Koke confront Dutch referee Danny Makkelie during the Champions League tie
Chelsea striker Alvaro Morata goes to ground after being challenged by defender Lucas who was then booked
Torres refused to celebrate when he scored against Atletico at the Bridge in a Champions League semi-final in 2014, a tie eventually won by the Spaniards.
Left-back Filipe Luis was another Atletico player back on familiar turf but there was no sign of Diego Costa as he counts down the days until he can finally play again in January.
Atletico’s frantic intent set the pattern of the game although their situation filtered through to their football.
Simeone’s team committed numbers forward at speed but they often lacked composure around the penalty area and their passing was hurried and inaccurate.
Chelsea were content to draw the sting and threaten when they broke quickly out of defence with Morata the focal point.
Eden Hazard used his quick feet to beat a couple of Atletico Madrid defenders before shooting with his right foot
Atletico Madrid left back Felipe Luis stops Hazard in his tracks as the Belgium international sprinted towards goal
Chelsea goalkeeper Thibaut Courtois was forced into turning the ball over the bar after a strike from Fernando Torres
Morata spun and lashed one effort wide from 20 yards, tested Oblak with first-time shot from a low cross by Victor Moses and forced another save from the goalkeeper with a fierce cross-shot from the left.
Moses started at right wing-back with Davide Zappacosta switching to the left in order to give Marcos Alonso a breather.
Zappacosta, who scored on his Champions League debut against Qarabag in September, found his range again as he collected a pass from Cesc Fabregas and cut inside onto his right foot. Again Oblak saved.
Chelsea were into their best rhythm as the interval approached. Ngolo Kante was winning the ball in midfield, Fabregas was picking passes and Eden Hazard dribbled dangerously into the spaces Atletico left behind them.
Lucas Hernandez was booked for cutting down Hazard. Gary Cahill escaped with a warning despite accidentally volleying Antoine Griezmann as he was beaten to a bouncing ball on the edge of the Atletico penalty box.
Atletico Madrid midfielder Gabi tries to win the ball back off Chelsea’s Tiemoue Bakayoko during the first half
With his team needing a win, Atletico Madrid manager Diego Simeone didn’t stop shouting instructions from the touchline
Griezmann was on floor again, in almost the same spot, early in the second half, although this time he was barely touched by Andreas Christensen.
Dutch referee Danny Makkelie thought it was foul, however, and Griezmann swerved the free-kick over the wall.
Thibaut Courtois made a routine save. At the other end, Oblak denied Christensen and Morata, again, and Hazard fired wide another wonderful jinking run which left a trail of bodies behind him.
Filipe Luis hit a post from 25 yards and Koke’s attempt to follow in the rebound with a diving header was gathered by Courtois.
But the Chelsea goalkeeper was beaten when Torres touched on a corner at the near post and Ninguez escaped Tiemoue Bakayoko all too easily to convert with a simple header at the back post.
It would be the final touch for Torres who received a warm applause from the home fans as replaced by Yannick Carrasco.
Conte threw on attacking players and Chelsea pulled level but there would be no winner and suddenly Monday’s draw seems a little more daunting.
Chelsea defender Gary Cahill manages to win the ball off Atletico Madrid forward Antoine Griezmann during an early battle
Chelsea midfielder Cesc Fabregas heads clear of danger after an early Atletico Madrid attack in the first half
Antonio Conte’s Chelsea had already qualified for the knockout stages but were aiming to finish top of Group C
Atletico Madrid went into the match on Tuesday night needing a win if they were to progress from the group stages
Atletico Madrid’s players had to rush their pre-match warm up after arriving late at Stamford Bridge on Tuesday night