Valencia had a chance to win it at the end but have to settle for a 2-2 draw with Chelsea.
It was all level at the break after Soler opened the scoring with a volley in the box and Kovacic equalised with his first goal for Chelsea less than two minutes later.
In the second half, Pulisic gave Chelsea the lead after a lengthy VAR check showed he was onside.
Parejo then saw a penalty saved by Kepa before Wass scored a stunning goal from the right wing. Rodrigo could have won it right at the death, but missed a sitter from close range.
Chelsea could certainly have won but also lost given Valencia’s chances. Instead they will in all likelihood progress by beating Lille at home in the final game; a complication that would have been unnecessary were it not for a horrible error that earned Valencia a point.
That was the equaliser that was. The winner that wasn’t, and then was, and then wasn’t a winner after all, came after 53 minutes when a cross from N’Golo Kante was knocked down by Kurt Zouma.
Christian Pulisic pounced on it to score from close range but was immediately flagged offside.
At which point the VAR check kicked in, with referee Felix Zwayer stalked around the penalty area by a delegation of protesting Valencia players, led by centre-half Ezequiel Garay.
Wherever he went, they went, even though the decision was now out of his hands.Three minutes became four. Chelsea lined up to face a goal kick. And then the clarification came.
Pulisic was onside. Now Zwayer was not stalked but chased. Finally, he summoned the courage to do what he should have done earlier. He booked Garay. That stopped it. He should have booked more.
Were the officials weak again for the penalty? There certainly appeared minimal contact between Jorginho and Jose Gaya and Zwayer was some distance away but very keen to give it.
No clear and obvious mistake VAR decreed, so Daniel Parejo stepped up, hit hard, high and left and Arrizabalaga pulled off the most stupendous save. Did it compensate for what followed, though? Not really.
Chelsea should be through now. Combined with the injury to Tammy Abraham – who went to hospital having landed awkwardly – this was a costly night.
Frank Lampard would not have appreciated Valencia’s opening goal. He would, however, have recognised the method and execution. It was the type of goal he once scored, for Chelsea.
The same intent, directness, eye for the opportunity. Rodrigo was afforded too much time and space on the right, enough to whip in a dangerous cross.
Carlos Soler, a midfielder who starts wide on the left but comes inside at every opportunity, was the beneficiary.
He was late, with the benefit he could identify the gaps in Chelsea’s resistance and gamble on where the ball would arrive. He aimed for the six yard box, as a certain former Chelsea midfield player used to.
It’s a devilishly hard run to pick up, as Lampard knows, and when Soler met the ball first time it gave Chelsea goalkeeper Kepa Arrizabalaga no chance, despite getting a hand to it.
Having enjoyed the best of the possession if not the chances in the first-half, Lampard must have felt sick.
Fortunately, Valencia are flaky, a mid-table La Liga team whose limitations showed in the way they refused to press Chelsea, dropping off, dropping deep, seeking safety in massed, banked numbers.
On this occasion they were well equipped to deal with a Cesar Azpilicueta ball into the area, which appeared to be repelled by two heads at once.
The ball looped out and fell to Mateo Kovacic who returned it, a low shot to the near post that didn’t look up to much but defeated goalkeeper Jasper Cillessen and crept in, his first for the club.
Chelsea had their chances, too, but will have been more concerned with the injury to Tammy Abraham that happened before half-time.
He jumped for a ball and landed awkwardly, perhaps on the leg of another player. Limping around the side of the pitch, he eventually climbed on a stretcher and was carried down the tunnel. It didn’t look good.