Dramatic draw against Werder Bremen
Spanish defender Puyol's blushes were spared when substitute Messi finished neatly in the 89th minute after the Germans had held their advantage for much of the second period.
Having lost twice to Barcelona in last season's Champions League group stages, Bremen were in no mood to fold easily this time around and they carved out an opportunity as early as the second minute.
In fact, Aaron Hunt latched onto an inviting through-ball from Tim Borowski, but his weak finish landed comfortably in the hands of Victor Valdes in the Barcelona goal.
Barcelona were looking vulnerable to the attacking presence of Hunt and Miroslav Klose as Werder, seemingly thriving on their billing as underdogs, grasped the upper-hand.
Samuel Eto'o, however, was looking lively and in the 23rd minute he sent in a right-footed attempt from 25 yards out, but Wiese was equal to it.
Ronaldinho also found himself with space in the area mid-way through the first half but he was thwarted by Christian Schulz's bullish tracking.
At the other end, it was Hunt who was creating the bulk of the German side's chances and he tested Valdes again on the half-hour mark. Hunt unleashed an effort from just outside the box which the Barca keeper had to get down low to his left to catch.
Barcelona started the second-half with renewed purpose and a Ronaldinho corner straight after the break should have been converted. A teasing ball into the danger area was missed by three orange shirts, with Ludovic Giuly most culpable.
Klose connected with a Diego corner in the 50th minute but his downward back-post header dropped inches wide of the Barca goal.
Bremen's breakthrough was not far away, and in the 56th minute Puyol guided an inswinging Hunt shot into his own goal.
Hunt's cross from the left flank was pitched into the danger-area and a fully-stretched Puyol, under pressure from Tim Borowski, volleyed past a helpless Valdes.
Barca's luck was to worsen five minutes later when Eto'o was stretchered-off following an innocuous looking fall. He was replaced by Eidur Gudjohnsen, while Messi also entered the fray in place of Giuly.
Borowski went close on 65 minutes but his angled drive from the edge of the box flew marginally wide of Valdes' left post. Moments later, Klose sent a rasping drive goalbound but good hands from Valdes kept it out.
With 15 minutes remaining only a fantastic save from Wiese kept out Messi after the Argentinian had jinked his way expertly into the box.
However, there was no stopping Messi a second-time and after tidy link-up play with Deco on the edge of the Bremen box, the youngster ran on to plant a lethal finish past Wiese and clinch what could prove to be a crucial draw.