Bayern Munich were left to rue missed chances as they lost their 100-per cent record in the UEFA Champions League with a 1-1 draw in Naples.
The point enabled the Bavarian giants to preserve their advantage at the top of the table - but they would have had all three had Mario Gomez not seen a 49th-minute penalty saved by Morgan de Sanctis. Toni Kroos gave the visitors an early lead, only for Holger Badstuber's own goal to level things up before half-time.
Bayern coach Juup Heynckes said he felt his team were well on course to reaching the second round despite the draw. "Obviously we came here to win even though we were up against a good side. Maybe I'm satisfied with a draw even though given the way we played in the second half we deserved to win.
"I'm not a prophet, right now it's difficult to assess. We started the group well and now obviously we're going back to play at home. We're quite confident in our chances of qualification, but Napoli also have a chance."
The visitors were quick out of the blocks and took the lead inside two minutes, with Kroos supplying the finish to Jerome Boateng's cross from the right. Napoli hot-shot Edinson Cavani tried his luck in the seventh minute but his right-foot effort from 20 yards went wide.
Bayern threatened with efforts from Philipp Lahm and Mario Gomez, before Cristian Maggio's 21st-minute effort for the hosts failed to test visiting goalkeeper Manuel Neuer. Daniel van Buyten's 26th-minute shot was blocked by Paolo Cannavaro, then Jerome Boateng's volley for the visitors was parried by De Sanctis as the visitors continued to look the more threatening.
However, the home side were level in the 39th minute when Holger Badstuber - earlier booked for a foul on Ezequiel Lavezzi - headed into his own net from close range as he attempted to deal with a Maggio cross. The visitors were given a great opportunity to regain the lead when Cannavaro was penalised for handball inside his own penalty area. However, Gomez's placed penalty was comfortably kept out by De Sanctis.
Bayern continued to pose more of a threat, with Thomas Muller shooting wide in the 55th minute and Anatoliy Tymoschuk doing likewise four minutes later. With 15 minutes remaining Kroos came close to a second goal but Walter Gargano blocked his 25-yard effort.
In the 86th minute Bastian Schweinsteiger's 18-yard effort was saved by De Sanctis - but Napoli held on for a point which keeps them in second place in the group, despite Manchester City's 2-1 win over Villarreal.