On top of Europe in January. Out of the Champions League by early March.

Liverpool's reward for dominating the competition's new-look league format was to run into a roadblock in the shape of Paris Saint-Germain in the round of 16.

Liverpool coach Arne Slot described his team as "so, so, so unlucky" to come up against "one of the best teams in Europe" after losing 4-1 in a penalty shootout at Anfield in Liverpool on Tuesday.

"That's the format we are in, and we have to accept it," he said.

The round-of-16 contest finished 1-1 on aggregate after Ousmane Dembele's first-half goal Tuesday canceled out Liverpool's 1-0 advantage from the first leg in Paris.

It is one of the quirks of the revamped Champions League that, despite topping the league phase with wins against European giants Real Madrid, Borussia Dortmund and AC Milan, Liverpool then had to face a resurgent PSG squad, which had to rely on the lifeline of the playoffs to advance to this stage.

"We go out in a way that, I think, impressed Europe. But, it is something, now, to take into consideration, whether it is worth ending up first in the league table if you can face Paris Saint-Germain in the next round," Slot said. "But, in the end, if you want to win the tournament, you have to beat teams like Paris Saint-Germain, and that's what we didn't do today."

The PSG performance that triumphed at Anfield looked markedly different to the one that struggled in the early stages of the competition — when the team lost to Arsenal, Atletico Madrid and Bayern Munich, as well as dropping points against PSV Eindhoven.

The French champion showed it was a threat by beating Manchester City 4-2 in January, and had dominated Liverpool in Paris before falling to a late sucker punch from Harvey Elliott.

It had to ride a storm at times in the second leg — including surviving a Jarell Quansah header that hit the post — but Liverpool goalkeeper Alisson Becker also had to pull off a string of saves to keep the home team in contention.

"It was the best game of football I was ever involved in," Slot said.