Former Arsenal captain Thierry Henry knew full well not to write off his old team-mates as Barcelona looked to secure a place in the Champions League semi-finals.
The holders were in complete control following a blistering start and a second-half double from Zlatan Ibrahimovic in Wednesday night's first leg at the Emirates Stadium.
However, the Gunners fought back through Theo Walcott before a late penalty from captain Cesc Fabregas, who played on despite a broken leg, gave the Premier League side hope when they travel to the Nou Camp next week.
Henry - who scored a club-record 226 goals in 380 appearances for Arsenal before leaving in the summer of 2007 - always felt Arsene Wenger's youngsters would rise to the challenge.
"I was not surprised by what the Arsenal team did, not with these fans," said Henry.
"I have said it so many times that it always helps. They can be 2-0 down at home and if your fans start to boo you then it's a different story - but the Arsenal fans were helping them, trying to make them come back in the game.
"However, I am not surprised at all because I know what can happen here."
Henry added: "It did not look like they could come back, but at the end of the day they did it.
"That shows a team which is in the quarter-finals are difficult to beat.
"We need to be aware of a team like that.
"We do not concede a lot of goals, but they scored two against us, so that is a sign."
Henry, 32, came on for the second half, and was given a warm reception by the home supporters, many of whom stayed to clap him off at the full-time whistle.
"There was a lot of emotion and there was a special moment at the end," the France international told reporters.
"Like we always do as a team at Barcelona, we went to say thank you to our fans.
"What happened after that, I never imagined. I would like to thank the Arsenal fans for the welcome back.
"I have great love for the club and I think the fans still love me. It was amazing."
Henry - who helped guide the Gunners through one of the most successful spells in their history - makes no secret of his affection for Arsenal.
"Now I play for another team and will compete for another team, but it reminded me of the bond, the love I have with the club and the fans," Henry, signed by Wenger from Juventus in 1999, told Arsenal TV Online.
"The reception when I came on and then at the end made it difficult for me to leave the pitch.
"I did not want to leave the pitch and the fans did not stop clapping, it was amazing and no words can describe the feelings I had.
"I just love the club, everything I did was tremendous and that is all still there."
Henry believes Arsenal could yet still have a say in the title race, with top two Manchester United and Chelsea to play each other this weekend.
"The Premier League race is tight, but even after the defeats to Manchester United and Chelsea I was saying they can win it - and I still think they can," the Barcelona forward insisted.
"As I always said in my time here, as long as it is mathematically possible, then you have a chance."
