Unfortunately referee Mark Halsey had a nightmare game with vital decisions which pleased Arsenal but angered Villa and had a direct bearing on the outcome of the match.
The first was a free-kick of dubious origin and a second was a penalty which was converted by Henry, allowing the more worldly Gunners took full advantage against a hoodwinked Villa side.
Arsenal were generally the superior side with Patrick Vieira the midfield general and Kanu always a problem for the Midlands club.
The Gunners defence was as solid as ever with Pacal Cygan dominating Juan Pablo Angel to such an extent that the Colombian international was completely shut out.
Villa had every reason to be aggrieved with the opening goal from Henry which came from a free-kick after Vieira appeared to dive following a tackle by Olof Mellberg.
As Halsey moved away from speaking to Henry the Gunners striker stroked the ball low past the disorganised defensive wall and into the net past a totally unprepared Thomas Sorensen.
The Villa players were very upset at Arsenal's smart gamesmanship and objected strongly with Mark Delaney being booked for his trouble.
Villa battled gamely against Arsenal's superb skill and their only real scoring opportunity occurred shortly before the Gunners took their surprise lead.
Angel produced a fast cross from the right which Marcus Allback, making his first appearance for over a month, screwed wide as he was falling back.
Seven minutes into the second half Kanu worked his way through Villa's defence. In the process he attempted to shoulder charge Mellberg and bounced off the Villa skipper and onto the ground, to earn a penalty which was duly converted by Henry.
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.
Booked: Vieira.
Attendance: 39,380.
Referee: M Halsey (Lancashire).