Bayer Leverkusen remain in pole position to qualify as winners of Group C, but have failed to find a breakthrough before half time in their Champions League clash with Benfica.
Hakan Calhanoglu tried to get the visitors off to the perfect start after nine minutes only to see his right-footed shot from the edge of the area blocked by the retreating home defence.
However, Benfica showed plenty of early fight and Ola John squandered two chances to give the Eagles the lead in their final game of the campaign.
Calhanoglu tried to forge a lead for Roger Schmidt's men from a free kick midway through the half, but the Turkish international's speculative strike failed to test keeper Artur.
Later in the half, Bayer could have edged in front when Simon Rolfes played in Roberto Hilbert only for the defender to drag his effort wide.
With half time approaching, Josip Drmic was also denied the chance to give the visitors a crucial advantage after good work from Artur.