Barcelona's hopes of progressing to the last 16 pf the Champions League all hinge on the final matchday of Group E after the Spanish club were held to a 0-0 draw against Benfica on Tuesday.
With Xavi making his Champions League debut in the dugout, the Catalan side produced a performance a world apart from the sorry outfit Benfica saw off 3-0 in Lisbon in September.
A win would have earned Barca qualification alongside Bayern Munich, whom they must now beat on December 8, if Benfica beat Dynamo Kiev, to reach the knockout round.
Ronald Araujo, the Barcelona defender who had a late effort disallowed, told uefa.com: "We played exactly the game the boss asked us to, pressing high up the pitch in particular. All we lacked was the crucial goal."
In front of almost 50,000 fans braving a wintery evening in Catalonia, Barca dominated the match with on-loan winger Yusuf Demir denied by the woodwork in the first half.
Frenkie de Jong thought he had broke the deadlock on 68 minuted but Odysseas Vlachodimos produced a superb save to tip the Dutch midfielder's header over the bar.
With the clock ticking down, Araujo thought he had delivered the decisive moment but his effort seven minutes from time was ruled offside.
Four minutes of injury time proved no place for the faint-hearted, as both sides went all out for the winner.
And Benfica it was who almost got it, with visiting boss Jorge Jesus crumpling to his knees after watching Haris Seferovic fluff a great chance with only Marc-Andre ter Stegen to beat.
As it was, the stalemate left Barca in second on seven points, two ahead of Benfica, and their Champions League fortunes resting on a result in Munich in two weeks' time.