The Nigerian forwards were both on the score sheet as the Premier League side came from a goal down to maul Blackburn Rovers at Erwood Park.
Emmanuel Emenike got his West Ham career to a brilliant start after grabbing a sweet brace either side of a Dimitri Payet double in his first start for the club he joined on loan in January.
West Ham United progressed to the quarter-finals of the FA Cup thanks largely to the performances of their Nigerian imports and the excellent Frenchman after dispatching 10-man Blackburn Rovers.
The Premier League side started well but were pegged back by a stunner from Ben Marshall after just 20 minutes. But the Hammers were back in it just 6 minutes later when Victor Moses picked the ball from the half way line and ran the entire distance before hammering an unstoppable 20-yard strike past Jason Steele in goal for the Championship side.
Dimitri Payet then responded with an excellent free kick straight into the top corner from 25 yards to edge West Ham ahead into the break.
Blackburn’s Chris Taylor then got himself sent off after a needless challenge on Moses after which the home side imploded.
First, Emenike slammed home his first goal for the Slaven Bilic’s side off an assist from Kouyate. Kouyate himself would get sent off to reduce West Ham to 10 men but the damage had already been done to Blackburn’s confidence.
Emenike scored his second after 84 minutes, to send some of the sparse 18,793 crowd home early, as did Payet, also with his second, in added time.
The Hammers will now travel to the winner of the tie between Shrewsbury Town and Manchester United in the quarter-final.