Nicklas Bendtner fired a hat-trick as Arsenal recovered from their League Cup Final loss to Birmingham City in a one-sided fifth-round replay against Orient to set up a titanic quarter-final against Manchester United.
The Gunners' victory was never in doubt after Marouane Chamakh and Bendtner put Arsenal 2-0 up and Arsene Wenger's side bounced back emphatically from Sunday's shock defeat by Birmningham.
"It was important we came back from Sunday's defeat with a win," Arsenal manager Arsene Wenger told reporters.
"We are having a fine run apart from Sunday's defeat which came under special circumstances. But we played very well tonight."
The Gunners, held to a 1-1 draw by third tier Orient in the first game, were looking for a rapid response after Sunday's painful 2-1 loss when they conceded a last-minute goal to Birmingham after a mix-up between goalkeeper Wojciech Szczesny and defender Laurent Koscielny.
Chamakh settled nerves with a well-taken side-footed goal, his first since November, after seven minutes before Bendtner headed the second, Arsenal's 100th of the season in all competitions.
Orient, who scored in the last minute to take the tie to a replay, had chances in the opening stages with Dean Cox almost cancelling out Arsenal's opener after 14 minutes.
Bendtner's second just before half-time exposed the gulf in class between the teams when he beat off defenders before firing a curling shot past goalkeeper Jamie Jones.
The ball bounced off the shoulder of Ciaran Clark and into Toure's path and he cracked it home from inside the six-yard box.
Mario Balotelli, beginning to settle at City after a difficult first few months at Eastlands disrupted by injury, added the second when he collected a pass from Toure and sidefooted home a half-volley from 15-metres that bounced in off Brad Friedel's post.
