But before a frantic final 20 minutes, Barcelona looked like a team at least intent on renewal, diligently obeying the wishes of their new coach, despite Xavi's tenure being only two weeks - and in terms of training sessions, a few days - old.
Two 17-year-old wingers, Gavi and Ilias Akohomach, clung to the touchline to stretch the opposition defence.
Frenkie de Jong and the 19-year-old Nico Gonzalez were prepared to leave gaps behind them to be more advanced in midfield. Everyone pressed higher and faster.
Exuberance seemed to have been encouraged, although Xavi wanted more. "We need to take more risks," he said afterwards.
The question now is how much can they risk against Benfica, when the pressure is greater and the margin for recovery so small? And are his team brave enough to do it?
Last week, Spain faced Sweden in Seville, with automatic qualification for next year's World Cup in Qatar at stake. Spain won 1-0 but there had been gasps and groans as their team protected their lead with ambitious passing at the back.
"The temptation is to start to play long balls, to defend, to try to close the spaces, but you know what? If we play like that, we're not very good," said Spain coach Luis Enrique, who coached Barcelona and Xavi between 2014 and 2017.
"The players I've picked are not the best ones to launch missiles, they're the ones to have the ball, to press high, to make the pitch bigger and while that gives people a heart attack, it gives us the chance to play the game how we want to."
In the same way, Barcelona must now stay true to Xavi's convictions in the heat of the battle against Benfica.
For the best part of an hour, they were liberated against Espanyol. The chances were rolling in, the fans were bouncing again and the players were enjoying themselves.
But as it became clear the game would not be won easily and the result would be in doubt until the end, all the newly-adopted principles that had previously been crisp and clear became blurred. Under pressure, Barca lost sight of Xavi's plan.
Xavi was asked afterwards if the fade had been physical.
"I don't see it as a physical problem, it's problem of understanding the game," he said.
"We had to go at the opposition, dominate, have the ball. It's not a physical problem, it's a football problem."
In La Liga, Barcelona are six points behind the top four but there are 25 games left to make up the gap. As well as Real Madrid and Atletico Madrid, they have Sevilla, Real Sociedad and Real Betis in front of them, all of whom they can hope to overtake.
In the Champions League, they are two points ahead of Benfica in Group E but lose, or even draw on Tuesday, and there may be no way back.
Barcelona's last game is away at Bayern Munich, who are top with four wins out of four, while Benfica finish at home to Dynamo Kiev, who are bottom and yet to score a single victory.
It means Xavi's second game is an early test, not so much of his methods, which will need longer to be honed and measured, but his team's conviction in carrying them out.
"After winning that first game we are calmer, a victory gives us peace of mind and boosts our morale," said Xavi. "But Tuesday is another battle and we cannot ignore our principles. It's another final for us."