Barcelona looked to be heading for their first defeat in this competition for 18 months after their captain Carlos Puyol, who lifted the trophy for the Spaniards last season, had scored a terrible own goal on 56 minutes.

But in the 89th minute 19-year-old substitute Messi, on the pitch for just over 20 minutes, latched onto a fantastic pass from Portuguese international Deco to rifle in an equaliser.

"It was a difficult game and a real fight right until the last minute," said Barcelona coach FranK Rijkaard.

"There were two good teams out there tonight and I think a draw was the fair result.

"I said there were no easy games in the Champions League and that was emphasised tonight. It was a good result for Barcelona."

Barcelona now have four points, after their 5-0 hammering of Levski Sofia in their first match, while Chelsea top Group A with a perfect six points having beaten Levski 3-1 on Wednesday.

Bremen, who lost 2-0 to Chelsea in their first match, have just one point to show for their efforts and could rue that late Messi equaliser.

Barcelona's next match is at Chelsea, who they eliminated at the last 16 stage last season, on October 18, while Bremen take on Sofia on the same day.

"We are all bitterly disappointed and should not allow that to happen -- particularly in the 89th minute," said Bremen goalkeeper Tim Wiese.

"We did enough to win but Barcelona are a great team and can always create something.

"Messi took his goal brilliantly but the fact that it was so late on makes it even more painful."

Rijkaard drafted in French international defender Lilian Thuram and midfielder Thiago Motta after resting the pair in the weekend's 1-1 draw with Valencia.

Bremen sprung a few surprises in their line-up with German international defender Per Mertesacker, a five-million-euro signing from Hannover, making his debut for the club. Brazilian playmaker Diego also recovered from a knee injury to start while Germany's World Cup finals golden boot winner Miroslav Klose shrugged off an ankle injury to return in attack.

Bremen, lying a disappointing ninth in the Bundesliga, were not intimidated by the champions of Europe and had a good opening early on with German international Torsten Frings shooting inches wide of the post after a mix-up in the Barcelona backline.

"I would have settled for a 1-1 before the match but it goes without saying that we are disappointed at conceding the equaliser so late on," bemoaned Frings.

Spanish champions Barcelona were spreading the ball around with real panache but, while it was pleasing on the eye, the usual cutting edge was missing.

Cameroon international striker Samuel Eto'o spurned Barca's best, and only, real chance of a below-par first half with Wiese using his legs to block his goalbound shot.

At the start of the second half the Spanish visitors pushed on but Bremen took the lead in the 56th minute with Barcelona skipper Puyol putting through his own net.

Aaron Hunt crossed from the right and Spanish international Puyol got his clearance all wrong as the ball squirmed off his shin and past goalkeeper Victor Valdes.

Tim Borowski went centimetres from adding a second for the hosts ten minutes later with his shot flashing across Valdes' goal.

Bremen looked to have done enough for a historic win but then Messi popped up at the death to salvage a point for the holders.