Chelsea boss Enzo Maresca said he could have blown his side's chances of hanging on for a 1-0 win over Tottenham Hotspur on Thursday by making defensive changes for the dying moments, only to realise that a full 12 minutes had been added on.
"We created chances enough in the first half, and then, to be honest, it has been my mistake because I did the change before I saw the extra time," a relieved-looking Maresca told reporters.
"When I saw 12 minutes, I saw that probably was too early to make that kind of change. But fortunately, we won the game, and we are happy."
With the clock ticking down, and Chelsea ahead through Enzo Fernandez's 50th-minute header, Maresca replaced attacker Cole Palmer and Fernandez with defender Tosin Adarabioyo and midfield anchor Kiernan Dewsbury-Hall, packing his back line.
The change allowed Spurs to pour forward in their search for an equaliser during the long period of stoppage time, which came after two long VAR checks in the second half which ruled out goals for both sides.
Maresca was full of praise for the way his players soaked up the pressure to seal the win which gave Chelsea some fresh momentum in their hunt for a top four finish and a place in next season's Champions League.
"If you want to become a team, I think you need also to learn and to play in the way we played in the last 10 minutes: win a game in a dirty way," the Italian said.
Maresca said the return of Senegal striker Nicolas Jackson from injury had given his side more shape, thanks to his incessant pressing of the Spurs defence. "For sure, with Nico we are a different team," the manager added.
Spurs boss Ange Postecoglou said poor defending was to blame for Chelsea's goal and he was critical of how VAR ruled out what he thought was an equaliser when substitute Pape Sarr beat Robert Sanchez with a low drive, only for it to be ruled out for a foul by Sarr moments earlier.
The Australian downplayed suggestions from reporters that he had shown frustration at Spurs fans - some of whom had booed his substitution decisions - by cupping his ear to them when Sarr found the back of the net.
"It's incredible how things get interpreted. We'd just scored. I wanted to hear them cheer. We've been through a tough time and I thought it was a cracking goal. I wanted them to get really excited," he said.
"It doesn't bother me. It's not the first time that they've booed my substitutions. That's fine. They're allowed to do that," said Postecoglou, whose side sit a lowly 14th in the league standings.