Points shared in Belgrade
Red Star Belgrade marked its return to Europe's grand stage with a battling 0-0 draw against a frustrated Napoli at Rajko Mitic Stadium.
The highly-fancied visitor probed patiently from start to finish but were unable to deny the Serbian champion a hard-earned point on ita first appearance in the competition for 26 years.
Though Lorenzo Insigne and Mario Rui both struck the crossbar either side of half-time, it was a largely unconvincing way for Napoli to commence its Champions League campaign.
Carlo Ancelotti may instead have to manufacture positive results against both Liverpool and Paris Saint-Germain if his team is to escape a tough Group C.
Napoli's command of possession translated into few early scares for Red Star outside of an audacious Insigne rocket that came back off the woodwork.
Though his defence was under constant examination, Milan Borjan only had one real save to make before half-time, the goalkeeper smartly covering his near post to block Arkadiusz Milik's first-time effort in the 29th minute.
Napoli was again frustrated by the frame of the goal when Mario Rui skimmed a free-kick off the top of the bar soon after the restart as opportunities for the opener began to flow more regularly, Jose Callejon next having a mishit finish cleared off the line by Milan Rodic.
But genuine chances were ultimately too few to deserve a winner and the Serie A side could themselves have been punished late in proceedings, David Ospina up to the test of a Richmond Boakye shot from the edge of the area.