Liverpool manager Jurgen Klopp criticised Atletico Madrid for their negative tactics and accused Diego Simeone's side of trying to get Sadio Mane sent off as the Champions League holders suffered a 1-0 defeat in the first leg of their last-16 clash.
Saul Niguez's scrappy goal in the fourth minute was enough to settle the tie in a fervent atmosphere at the Wanda Metropolitano, scene of Liverpool's coronation as European champions for a sixth time a little over seven months ago.
But Klopp was unhappy with some aspects of Atletico's play. The biggest flashpoint of a fiery game saw Atletico loudly appeal for Liverpool forward Mane to be sent off for a second clash with Sime Vrsaljko after being booked for an earlier incident with the Croatian.
Klopp substituted the Senegal international immediately after the interval.
"The plan today was to get Sadio out of the game with a yellow card, I was a bit afraid that his opponent would go down if Sadio only takes a deep breath or whatever," said Klopp, who was booked for protesting on the sidelines.
"I didn't want to have that situation and that's why I took him off. He was targeted. It was clear. It's part of football but I don't like it."
If Liverpool remain favourites to go through, the roar from the Atleti fans at the final whistle, aimed at their fist-pumping players on the pitch, suggested Simeone's team now have belief.
"Tonight is one of those nights you don't forget," said Simeone. "We haven't gone through but we have beaten the best team in the world."
If Alvaro Morata had not slipped at the crucial moment, Atleti might even have taken a two-goal lead to Anfield, where they can expect an onslaught next month.
That miss could yet come back to haunt them. Klopp has overseen a number of inspiring second-leg comebacks in European matches at Anfield - none more memorable than overturning last season's 3-0 deficit to Barcelona in the semi-finals - and warned Atletico what awaited them on Merseyside next month.
"As long as we can get 11 players in a Liverpool shirt we will try with all we have. For all Atletico fans who have got a ticket, welcome to Anfield," he added.
"It's half time, we're 1-0 down, we wouldn't give up if we had 15 minutes of half time so why should we when we have three weeks, and even better, the second half will be played in our stadium."
The visitors were also riled by the celebrations of Simeone and some of his players at full time after they secured a victory that could kick-start at faltering season.
"They've celebrated as if they've won the tie after the game, so let's see," said left-back Andy Robertson.
"We've got a couple of weeks, Premier League business to take care of, and then we're coming back to Anfield.
"We know our fans will be there, we'll be there, so it's up to them to come as well."