Benfica and Monaco have proven inseparable at the halfway stage of their Champions League group match, going into the break with the deadlock intact.
The hosts were first to threaten, firing a warning shot in the opening stages when Eduardo Salvio went on a mazy run and let fly, forcing visiting keeper Danijel Subasic into a comfortable save.
Salvio caused Monaco more problems in the 12th minute, whipping in a cross from the right that eventually found its way to Nicolas Gaitan, who fired wide.
It was Gaitan who was at fault when Benfica almost fell behind in the 23rd minute, the Argentine giving the ball away cheaply to allow Monaco to stage a quick counter-attack.
Fabinho played a teasing ball into the box, which needed heroics from Julio Cesar to prevent it falling into the path of Lacina Traore for a tap-in.
Monaco had defender Andrea Raggi to thank for preventing them from falling behind moments before half time, the Italian producing a last-ditch block to stop Gaitan from finding the back of the net.
