Tempers frayed between the two sets of players in the closing stages
Chris Wood and Noni Madueke scored as Chelsea and Nottingham Forest played out a tactical and feisty draw at Stamford Bridge.
Forest went ahead when 32-year-old striker Wood slid in a finish past Robert Sanchez after a good set-piece routine involving James Ward-Prowse and Nikola Milenkovic in the 49th minute.
But Chelsea responded quickly as Madueke equalised eight minutes later after cutting in on his left foot and shooting, his fourth such effort having had the beating of left-back Alex Moreno.
Midfielder Morgan Gibbs-White came off injured in the second half - putting his chances of contributing with England this month in major doubt as he gingerly walked off the pitch, looking in pain and frustrated.
Referee Chris Kavanagh sent off Forest's Ward-Prowse for deliberately handling the ball to stop a Nicolas Jackson counter-attack in the second half, giving him a second yellow card, having booked him earlier on for a more conventional tactical foul on star man Cole Palmer.
Then, Madueke also appeared to go off injured after a melee sparked by Neco Williams, who pushed defender Marc Cucurella into Chelsea manager Enzo Maresca.
Chelsea looked to their extensive bench to win the match, bringing on Christopher Nkunku, Joao Felix, Mykhailo Mudryk and Pedro Neto to win the game with a man advantage, but Palmer had two chances well saved by Matz Sels and Felix headed an effort wide in stoppage time.
There were two huge efforts saved in the closing minutes.
Williams curling effort for the visitors was saved by Sanchez, before - at the other end - Nkunku's diving header was saved at close range by Sels.
Chelsea defenders Cucurella and Wesley Fofana picked up their fifth yellow cards of the season, meaning they will miss the trip to Liverpool after the international break.
Footage online also appeared to show Jackson pushing Forest defender Morato in the face during the on-pitch melee.
Chelsea will also get a £25,000 fine from the Premier League after picking up six yellow cards in the game, while both clubs will likely face a charge of failing to control their players after ugly scenes near the end of the match.
Otherwise, it felt like a close match of two in-form clubs pitting their records against each other - with Chelsea dominant in the latter stages.
The Blues' five-game winning run has ended but they remain unbeaten in the league since the opening match of the season, while Forest are undefeated on the road in six matches, their longest such run since 1995.
Forest red card made game more difficult - Maresca
Injured England internationals create concern for Carsley
Two of interim England manager Lee Carsley's stalwarts from the under-21s were injured at Stamford Bridge.
There was real concern when midfielder Gibbs-White was taken off after his powerful shot was blocked by Malo Gusto in the second half.
And, after a melee between the two groups of players, Madueke had to be helped off the pitch by goalkeeping coach Michele de Bernardin, unable to put weight on one of his legs.
It is unfortunate for Madueke, who excelled as the best attacker on the pitch, having had the majority of his side's efforts created through his power and skill - before a chaotic end of the match where Chelsea threw the kitchen sink at Forest to get the winner, while also giving a lot of chances away.
It is possible Madueke will miss out on England's upcoming Nations League games against Greece and Finland but Gibbs-White looks near certain to pull out, as he looked both in pain and devastated when coming off - despite the away end's best efforts to pick up his spirits by chanting his name.
There are also doubts about Levi Colwill's fitness after he was substituted while pointing to his hip.
Are Forest most advanced defensive team in league?
Both goalkeepers 'huge' in Chelsea draw - Nuno
Forest have taken a huge leap forward under Nuno Espirito Santo this season.
That 90 minutes could be painted as an example of everything the Premier League should be - as Forest competed manfully, physically and with incredible tactical nuance at Stamford Bridge.
They were previously seen as a low block, defensive team under Steve Cooper - and in the first season under the Portuguese - but they are now able to retain possession and press higher up the pitch, while still sitting off teams when needed.
There has been an evolution that has taken them to one of the best defensive records in the league - conceding fewer than Manchester City, with their rearguard action crucial to this result.
The one-on-one defending of Ola Aina was exceptional, the two centre-backs Milenkovic and Murilo are two of the most physically imposing in the league and Sels has solved the goalkeeping problems since promotion.
Between them, they managed to handle Ward-Prowse's red card in a masterclass of defending, wasting time and counter-attacking football that led to Williams and Jota Silva going close.
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