Barcelona have missed the chance to qualify for the last 16 of the Champions League with two games to spare having been held to a goalless draw by Olympiacos at the Stadio Georgios Karaiskaki this evening.
Juventus's draw with Sporting Lisbon in the group's other game meant that victory would have been enough for Ernesto Valverde's side - while also condemning their hosts to Champions League elimination - but a disappointing performance saw them fail to find a way past Olympiacos.
The match saw Valverde return to a club where he won three league titles and two Greek Cups during two separate spells in charge, but it was not a happy homecoming as Barcelona failed to score in a Champions League group game for just the second time in the last 48 attempts.
Barca, who were without the suspended Gerard Pique and injured Andres Iniesta, quickly took control of possession and created their first opening within three minutes when Nelson Semedo raced on to a ball over the top only to fire his effort straight at Silvio Proto.
The visitors were out of sorts for the most part, though, and they needed a fine last-ditch challenge from Samuel Umtiti to deny Omar Elabdellaoui a clear chance after 15 minutes.
Barca did respond with their best opening of the first half five minutes later when Lionel Messi peeled away to meet a low corner and saw his bobbling effort kept out by an unorthodox save before Luis Suarez missed the target with an outside-of-the-boot finish from a tight angle.
As has been the case of couple of times already in this Champions League campaign, it looked like it might take a moment of Messi magic to unlock Olympiacos and he almost provided it with a solo run which ultimately saw him denied by the feet of Proto.
The hosts were holding their own, though, and perhaps should have done better on the half-hour mark when Vadis Odjidja-Ofoe nodded the ball back to Kostas Fortounis, who blazed his resulting effort well off target.
Messi then drew a comfortable save from Proto with a 30-yard free kick, but Olympiacos were growing as a threat at the other end and had their best chance of the first half in the 37th minute when Fortounis flicked an effort straight at Marc-Andre ter Stegen.
Barca could have no complaints at going into the break still goalless, and things didn't improve much for the visitors in the second half as they continued to struggle to find their usual rhythm.
The visitors' best chance of the contest arrived shortly after the hour mark when Messi exchanged passes with Suarez, but the return ball was a little too deep for Messi and the Argentine could only steer his effort wide of the target.
It was a performance far short of Barcelona's usual standard, and it was typified by an under-par Suarez, who squandered another good chance with 10 minutes remaining when he hesitated while clean through on goal before lifting his finish over the onrushing keeper and onto the top of the crossbar.
With Suarez short of confidence it was typically Messi who looked like the only man who could save Barca, but the five-time Ballon d'Or winner was denied twice in the closing stages by Proto as Olympiacos held on for a hard-earned draw to give them their first point of the campaign.
The result keeps the home side's slim Champions League hopes alive until matchday five at least, with Olympiacos becoming only the second team to prevent Barcelona from winning in their last 15 outings.
Barca still lead the way in Group D, but they must wait until at least their next match against second-placed Juventus in Turin to guarantee their spot in the knockout rounds for a 14th consecutive season.
