Match ends, Valencia 2, Chelsea 2.
Chelsea will not know their Champions League fate until the final group games after they drew at Valencia in an incident-packed match.
The Blues looked set for a place in the last 16 after Christian Pulisic gave them a second-half lead and Kepa Arrizabalaga saved Daniel Parejo's penalty.
But with eight minutes remaining, Daniel Wass' intended cross from the right bamboozled Kepa, who appeared to misjudge its flight.
Maxi Gomez had missed two opportunities from close range for the home side before Carlos Soler gave the Spanish club a 40th-minute lead when he converted Rodrigo Moreno's cross.
However, Chelsea equalised 108 seconds later as Mateo Kovacic turned at the edge of the area and struck a low effort into Jasper Cillessen's right-hand corner.
The match was turned on its head in the 50th minute. when Pulisic fired in. His strike was flagged offside and looked so to the naked eye, but after a three-minute deliberation by the video assistant referee (VAR), the goal was given with replays showing Ezequiel Garay's boot played the Chelsea man on.
The next big moment in the match came in the 63rd minute when Valencia won a penalty following Jorginho's foul on Jose Gaya. But after a brief VAR check, Parejo spot-kick was brilliantly pushed away by Kepa.
Valencia, who created several clear-cut opportunities during the match, then spoilt Chelsea's night when Dane Wass fortuitously found the net with his deep cross.
Blues defender Kurt Zouma had a header cleared off the line and Moreno missed at the far post in a breathless finale to the contest.
Chelsea may have to defeat Lille in the final match to secure a place in the knockout round, with Ajax, who beat the French side 2-0, and Valencia still in the mix.
Late equaliser and Abraham injury dampen Chelsea's day
Chelsea might feel aggrieved and relieved about the result.
Some might criticise Frank Lampard's team for not playing more defensively after taking the lead, but this season's Blues have often thrown caution to the wind.
Kovacic and Pulisic were his standout players. Croat Kovacic produced yet another workhorse-like display in midfield and ended a run of 122 games without a goal when he drilled home from the edge of the area.
The ex-Real Madrid man should have another moments after the restart, but failed to produce enough of an angle on his shot.
That attempt was set up by Pulisic's superb mazy run. The American has had a dream start to his new career with the Blues and - when it was eventually given - celebrated his fifth goal in eight away appearances.
Aside from the late equaliser, the only other negative for Chelsea was striker Tammy Abraham's injury towards the end of the first half, when he was helped off the pitch after landing awkwardly following an aerial challenge.
Valencia wasteful at Mestalla
Valencia coach Albert Celades might get his forwards to attend early training on Thursday for some extra shooting practice.
Former West Ham target Gomez missed two simple chances from close range, Rodrigo failed to find the target with his chip when Kepa was stranded, Parejo missed a penalty before Rodrigo shot wide at the far post in the final few seconds.
The Spanish side had 18 shots in total.
Soler showed the others how it should be done with his coolly slotted finish; Wass' equaliser was one of the home side's few moments of good fortune in attack.
Pulisic in great form - the stats
- Chelsea have played more Champions League away games against Valencia without losing than any against any other opponent in the competition (W2 D2).
- Valencia have won just one of their eight Champions League matches against Chelsea (W1 D4 L3), with a 1-0 victory at Stamford Bridge in the reverse fixture in September.
- Chelsea have lost just one of their past 12 away Champions League matches in Spain, although eight of these contests have ended level (W3 D8 L1).
- Carlos Soler's goal was Valencia's 100th in the Champions League on home soil, joining Real Madrid and Barcelona as the three Spanish teams to have done so. Indeed, only England (four) has more sides to reach this landmark in the competition.
- Christian Pulisic has scored as many goals in his last seven matches in all competitions as he managed in the previous 36 beforehand (six goals - Borussia Dortmund and Chelsea).
- Since the start of last season, no Valencia player has scored more goals (three) or registered more assists (four) in European competition than Rodrigo Moreno.
On Saturday, the Blues are at home to West Ham in the Premier League (15:00 GMT) while Valencia host Villarreal in La Liga (20:00).
- 3CostaSubstituted forGameiroat 67'minutes
- 24GarayBooked at 53mins
- 5GabrielBooked at 87mins
- 20TorresSubstituted forCoquelinat 74'minutes
- 18WassBooked at 32mins
- 8SolerSubstituted forLeeat 78'minutes
- 15Vallejo Galván
- 1ArrizabalagaBooked at 78mins
- 28AzpilicuetaBooked at 55mins
- 7KantéBooked at 73mins
- 5JorginhoBooked at 7minsSubstituted forEmersonat 72'minutes
- 10WillianSubstituted forMountat 80'minutes
- 9AbrahamSubstituted forBatshuayiat 45'minutes
- Felix Zwayer
- Shots on Target
Second Half ends, Valencia 2, Chelsea 2.
Lee Kang-In (Valencia) wins a free kick in the defensive half.
Foul by Emerson (Chelsea).
Attempt missed. Rodrigo Moreno (Valencia) left footed shot from the centre of the box is close, but misses to the right. Assisted by José Gayá with a cross.
Attempt missed. Rodrigo Moreno (Valencia) left footed shot from the right side of the box is close, but misses the top left corner. Assisted by Daniel Parejo following a fast break.
Attempt saved. José Gayá (Valencia) left footed shot from the left side of the box is saved in the top left corner. Assisted by Kevin Gameiro.
Foul by José Gayá (Valencia).
Reece James (Chelsea) wins a free kick in the defensive half.
Attempt saved. Michy Batshuayi (Chelsea) left footed shot from the right side of the box is saved in the centre of the goal. Assisted by César Azpilicueta.
Foul by Daniel Wass (Valencia).
Emerson (Chelsea) wins a free kick in the defensive half.
Foul by Lee Kang-In (Valencia).
Mason Mount (Chelsea) wins a free kick in the defensive half.
Gabriel Paulista (Valencia) is shown the yellow card for a bad foul.
Mason Mount (Chelsea) wins a free kick in the attacking half.
Foul by Gabriel Paulista (Valencia).
Attempt missed. Kevin Gameiro (Valencia) left footed shot from the left side of the box misses to the left. Assisted by Rodrigo Moreno.
Offside, Valencia. Daniel Parejo tries a through ball, but José Gayá is caught offside.
Foul by Michy Batshuayi (Chelsea).