A stunning late strike from substitute Robert Pires was enough to claim the spoils for Arsenal against a battling Derby side at Pride Park.
The French midfielder had only just stepped on to the pitch when he blasted the ball into the back of the net after good work from Sylvain Wiltord and Thierry Henry.
The Gunners should have killed the game off in the first half and could have been made to rue their misses when Stefano Eranio cancelled out Kanu's earlier strike.
But that goal from Pires leaves Derby's Premiership future hanging in the balance and Arsenal's hopes of playing in the Champions League next season looking a little brighter.
The French connection
Kanu was a constant threat throughout and came close to a goal in the opening minute.
The Nigerian wriggled through the defence and only the alert Mart Poom kept the ball out of the net.
The opening exchanges were scrappy and untidy but the visitors always looked the more likely to score.
It was the lively Kanu who broke the deadlock. With Ashley Cole probing forward, Wiltord received the ball on the left and crossed for the Nigerian to tap in from six yards.
Arsenal's provider and scorer again linked up well just minutes later.
With Horacio Carbonari floundering on the penalty spot, Kanu was allowed to volley into the ground and the outstretched Poom denied Arsenal a second goal.
With David Seaman probably wondering why he had bothered to turn up, just seconds before the half-time whistle blew, he was picking the ball out of the net.
Rory Delap forced himself wide on the right and his deflected cross fell for the unmarked Eranio, who delighted the home crowd to head in from three yards.
The second half opened in dazzling fashion.
Kanu almost stabbed home but Poom saved well again, and then Derby immediately romped forward and had a penalty appeal turned down after Cole appeared to handle.
Carbonari came close to nicking a goal with a rasping free-kick from 35 yards but with the introduction of Pires and Thierry Henry, it was the visitors who stepped up the pace.
Patrick Vieira was in inspired form, directing proceedings from the middle, and almost grabbed the glory but headed just wide from the six yard line.
Any thoughts of Jim Smith smiling will, for the time being, be put on hold.
Derby: Poom, Delap, Riggott, Carbonari, Higginbotham, Boertien, Eranio, Burley, Johnson, Kinkladze, Christie. Subs: Burton, Gudjonsson, Mawene, Murray, Grant.
Arsenal: Seaman, Dixon, Keown, Adams, Cole, Vieira, Lauren, Ljungberg, Grimandi, Kanu, Wiltord. Subs: Pires, Manninger, Henry, Parlour, Upson.
Referee: G Barber (Tring)