A double strike from Thierry Henry fired Arsenal back to the top of the Premiership table.
The Gunners striker scored with a quickly-taken free-kick in the first half that led to furious protests from the Aston Villa players.
Henry added his 19th goal of the season from the penalty spot in the second half after Kanu had been fouled.
Villa had their own chances, but Juan Pablo Angel and Marcus Allback failed to find the target.
The hosts started brightly, taking the game to Arsenal.
They hustled and harried Arsene Wenger's men, which left the Gunners struggling to get into their stride.
28 mins: Henry scores with a free-kick
53 mins: Henry converts penalty
Thomas Hitzlsperger and Gareth Barry were busy in the Villa midfield, while the in-form Angel looked a threat.
But Arsenal gradually imposed themselves on proceedings and looked fluid going forward.
Freddie Ljungberg and Robert Pires combined well, dissecting the Villa defence with some exquisite interplay.
Pires almost opened the scoring with a rasping volley from the edge of the area after a poor clearance by Jlloyd Samuel.
But Thomas Sorensen retrieved the situation by brilliantly tipping the ball over the crossbar.
Pires forced another fine save from Sorensen as Arsenal increased the pressure on Villa.
Henry suffered a blow to the face by Samuel's flailing arm. But the knock did nothing to dull the Frenchman's senses.
Patrick Vieira was brought down on the edge of the Villa area - prime free-kick territory for Henry.
While Villa were busy organising their wall, Henry despatched the ball through a mass of bodies into the back of the net.
Halsey (left) was at the centre of some contentious decisions
Villa's players were furious with referee Mark Halsey, who did not appear to signal clearly that he was allowing the Arsenal striker to take the kick quickly.
Before Henry's opener, Angel spurned a gilt-edged chance to give Villa the lead after he had been released by Mark Delaney's through-ball.
The Colombian striker's first-time, chipped shot was too heavy and the ball sailed over Jens Lehmann.
Allback almost restored parity for Villa before half-time, but his shot crept just wide of the post.
After the break, Villa poured forward in search of an equaliser and they peppered the Arsenal goal with shots, but could not find the quality to break through.
But any hopes of a comeback were dashed when Olof Mellberg body-checked Kanu in the Villa area, allowing Henry to convert the resulting penalty.
Villa did not let the second goal deflate them and credit must go to David O'Leary for forging a team prepared to fight on.
And on another day, against another team, some of Villa's play would have seen them secure three points.
But in this form, Arsenal are irresistible and they stretched their unbeaten run to an incredible 22 games.
Aston Villa: Sorensen, Delaney, Mellberg, Johnsen, Samuel,
Hendrie (De la Cruz 86), Whittingham, Hitzlsperger,
Barry (Ridgewell 86), Allback (Crouch 86), Angel.
Subs Not Used: Dublin, Postma.
Booked: Delaney, Mellberg, Whittingham, Barry.
Arsenal: Lehmann, Lauren, Cygan, Campbell, Cole,
Ljungberg (Parlour 76), Vieira, Silva, Pires (Edu 77), Henry,
Kanu (Toure 76).
Subs Not Used: Keown, Stack.
Referee: M Halsey (Lancashire).