Michy Batshuayi scored a late goal to help Chelsea scrape out a 1-0 win at Ajax in Champions League group stage action on Wednesday.
Batshuayi, who had come in as second-half substitute for Frank Lampard's side, hit the underside of the net in the 86th minute off a low cross from fellow sub Christian Pulisic.
The win extends Chelsea's unbeaten streak to nine in away matches in Europe, with their last loss at Barcelona in March 2018.
Pulisic brought added energy to the Chelsea attacks and Batshuayi finished sharply after earlier missing a seemingly easy chance just minutes after coming on as the manager's changes turned the tide in favour of the Premier League outfit.
"That's what you want from your substitutes, for them to stay positive and come on and do what they did tonight," Lampard told reporters after the match.
The teams went into the break at Amsterdam's Johan Cruyff Arena scoreless after a tense first half. Ajax seemingly took the lead in the 35th minute when Quincy Promes slotted in Hakim Ziyech's cross, but VAR ruled Promes offside.
Ajax kept up the attack following half-time but caught some bad luck in the 60th minute when Edson Alvarez's powerful header off Promes' corner kick ricocheted off the far post.
Chelsea had a good look in the 73rd minute when Pulisic's deflected shot fell squarely to Batshuayi at the six-yard box, who then sent it sailing over the bar.
But the two weren't to be denied again, teaming up in the waning minutes for the game winner as Pulisic's cross from the right caught the Ajax defenders moving out of position and allowed Batshuayi to slam the ball home.
"I'm delighted with the performance. Even if we had drawn 0-0 I would have been delighted, but we deserved to win," added Lampard.
"What a performance against a team that are fantastic on the ball. It was our work ethic and quality that proved the difference."
Ajax captain Dusan Tadic bemoaned too many errors on the part of the Dutch hosts.
Tadic said: "It was a 50-50 game. Chelsea are a good team but we could have done better. We were sloppy and made too many mistakes."
The two clubs meet again on Nov. 5 at Stamford Bridge in their next group outing.