Barca and Red Devils show value of persistence
Barcelona and fellow former Champions League winners Manchester United had to draw on all their class to come from behind and claim home wins against Celtic and Braga respectively.
Barcelona's last-gasp 2-1 win over the Scottish champions and United's 3-2 victory over Braga, which saw the English giants become only the second side to come back from a 2-0 deficit twice and win - the other being Arsenal - sees both of them needing just a point from their next games to seal a place in the knockout stages.
Celtic had taken the lead through an own goal by Javier Mascherano - completing a wretched few days for the Argentinian who was sent off at the weekend - but a superb goal at the end of the first half by Andres Iniesta levelled matters.
Despite a splendid rearguard action throughout the second half, Celtic succumbed to a goal by Jordi Alba - his first at the Nou Camp - in the fourth minute of time added on as Barca recorded their 100th win in Champions League competition.
Victory also saw Barcelona break their club record for an unbeaten run at home extending the present one to 18, with their last defeat coming against Rubin Kazan in October 2009.
"I think that our win was deserved," said Alba, who moved to Barcelona in the summer from Valencia.
"The strength of this [Barcelona] team, is that it resists till the end. A match lasts for 90 minutes and that is the length of time that Barca spends trying to score."
Celtic boss Neil Lennon said he couldn't be prouder of his side and relished the chance of a second go at Barcelona in Glasgow in a fortnight.
"They were brave and stuck with what I asked them to do," he said. "They defended brilliantly and at times we looked dangerous on the counter-attack. Everybody had written us off but I knew the quality of the character in the team. I look forward to doing it again in a couple of weeks."
Despite Celtic's bravura performance they only have a one-point advantage over Spartak Moscow, who grabbed their first win of the campaign after two defeats with a 2-1 home win over Benfica.
United had to rely on a brace from the outstanding Javi Hernandez and a messy one from Jonny Evans to storm back and take the three points after their fragile defence, which saw Rio Ferdinand rested, had conceded two early goals.
United manager Alex Ferguson said he was getting used to having to rely on his offensive players to get the side back into contention in matches.
"It's been the story of our season at home, starting badly and losing goals," Ferguson said.
"We have had to rescue games and it is the front players doing that. We played some terrific football tonight but it is a concern losing the goals."