Barcelona and Benfica could not be separated in a goalless draw at Camp Nou on matchday five of the UEFA Champions League.
This was Xavi's second game in charge since his appointment as Blaugrana manager and he made three changes to the side that saw off city rivals Espanyol on Sunday.
Clement Lenglet, Ronald Araujo and Yusuf Demir started in place of Eric Garcia, Oscar Mingueza and Ilias Akhomach.
A win for Barcelona would have guaranteed them qualification to the group stage for the 18th straight season.
Yusuf Demir and Jordi Alba both went close for Barcelona while Andre ter Stegen showed great reflexes to keep out Roman Yaremchuk's point-blank header.
Barcelona upped the ante in the final half-hour but they met an unbeatable Odysseas Vlachodimos in the Benfica goal.
Ronald Araujo thought he had put the hosts ahead with six minutes to go but the linesman correctly ruled the goal out for offside.
Benfica had a chance to win the game at the death after a quick counter. However, Haris Seferovic fluffed his lines with just the keeper to beat.
The draw means both sides still have a shot at qualifying for the knockout rounds ahead of matchday six in a fortnight.
However, Barcelona face the daunting task of trying to get something from Bayern Munich in Germany. Benfica will secure progress if they beat already-eliminated Dynamo Kyiv at home and Barcelona fail to win in Munich.
Here is a rundown of how the Barcelona players fared in the game.
Barcelona player ratings against Benfica
Marc-Andre ter Stegen - 7/10
The Barcelona goalkeeper was alert on the few occasions he was required and pulled off a stunning save to deny Yaremchuk in the first half.
Jordi Alba - 6.5/10
The Spain international forced the Benfica goalkeeper into a fine save in the first half but did not really impose his authority at either end.
Gerard Pique - 7/10
Pique made two clearances and two tackles to help Barcelona keep their clean sheet. He also had a shot at the other end that failed to hit the target.
Clement Lenglet - 6.5/10
The 26-year-old made two crucial interceptions for Barcelona and made way for Sergino Dest with four minutes to go.
Ronald Araujo - 7/10
The Uruguay international made five tackles and hit two shots off target before making way for Eric Garcia in the 86th minute. He had a goal disallowed for offside a few minutes earlier.
Nico Gonzalez - 7.5/10
Nico created a game-high four chances and had two shots - none of which hit the target. He also put in a defensive shift when needed.
Sergio Busquets - 7.5/10
The Spain international acted as the creative link between defense and attack for Barcelona. He created three chances for his teammates and also effectively shielded the defense.
Frenkie de Jong - 6.5/10
Frenkie de Jong hit the target with his sole shot on the night and ended the game with a pass accuracy of 80.3%.
Gavi - 6.5/10
The 17-year-old did not hit the target with any of his two shots on the night.
Memphis Depay - 6/10
It was a quiet night at the office for the Dutchman considering his usually high standards. He, however, did create two chances, none of which were converted.
Yusuf Demir - 7/10
Demir was Barcelona's brightest spark in the first half and he hit the post shortly before halftime. His impact waned after the break before being replaced by Ousmane Dembele midway through the second half.
Substitutes
Ousmane Dembele - 6/10
The Frenchman came on with 24 minutes to go and injected pace into the Barcelona attack.
Eric Garcia - 5/10
Eric Garcia came on in the final five minutes, so there was not enough time to make a mark on the game.
Sergino Dest - 5/10
Dest replaced Lenglet in the 86th minute and had just four touches of the ball before the blast of the final whistle.