But striker Nicolas Anelka, who made way for Henry with 20 minutes left, intercepted the pass after returning from an offside position and a promising opening was completely wasted.
Portsmouth had reason to complain that Adebayor was offside when the pass was played and they suffered a further blow as City doubled their lead in the first minute of injury time.
Anelka was wrongly ruled offside when a simple pass for Lampard to tap in awaited, before Drogba's backheel and Cole's lay-off gave Zhirkov a strike at goal which the Russian sent just wide.