Freddie Ljungberg scored twice as Arsenal cruised past Middlesbrough.
The Gunners took the lead when Ray Parlour stole possession and crossed for Dennis Bergkamp to slot home.
Joseph-Desire Job levelled by firing home Michael Ricketts' knock-down before Ljungberg slid home after Boro failed to clear Bergkamp's free-kick.
Ljungberg headed home after the break before Boro had George Boateng sent off, and sub David Bentley made it 4-1 with a delightful chip at the end.
After a bright opening with Boro trying to break quickly using the power and pace of Ricketts, Arsenal soon upped the tempo and began to dictate play.
19 mins: Bergkamp's shot goes in off Mills
22 mins: Job equalises
28 mins: Ljungberg restores Arsenal's advantage
68 mins: Ljungberg heads home to seal Arsenal's win
86 mins: Boateng is dismissed
90 mins: Bentley makes it 4-1
And with Pires prominent, they did not have to wait too long to go in front as the tie exploded into life.
Parlour chased down a lost cause on the right to rob Stuart Parnaby of possession and his pull-back was slotted home by Bergkamp via a deflection from Danny Mills.
But the home crowd were stunned into silence just three minutes later when Job latched onto Ricketts' header, held off Kolo Toure and slammed his shot past Lehmann into the roof of the net.
Back came the Gunners, and Ashley Cole's right-foot curler was magnificently tipped around the post by Schwarzer before Sol Campbell headed straight at the Australian from the resulting corner.
And they regained their advantage when Bergkamp's cross caused panic in the Boro box and Ljungberg pounced to rifle past Schwarzer from close-range.
Boro did have chances to go in at half-time on level terms, but Franck Queudrue headed wide and Stewart Downing fired past the post.
Seven minutes after the break Arsenal had two chances to extend their lead, but Edu mis-controlled in the area and then Bergkamp's drive was parried away by Schwarzer.
Bergkamp then sent Pires through, but the Frenchman's appeals for a free-kick after a clash with Mills were waved away by referee Mike Dean.
Although Arsenal continued to enjoy greater spells of possession they were struggling to find their usual fluency, clearly missing the scintillating skills of the rested Thierry Henry.
And the goal that ended the tie as a contest was a scrappy affair, Ljungberg nodding home from Pires' corner despite Gaizka Mendieta's efforts on the goalline.
With Arsenal content to sit on their lead Mendieta saw a shot pushed away by Lehmann before Boateng was sent off after two quick-fire bookings.
Arsenal substitute David Bentley rounded it off with a sumptuous chip over Schwarzer from the edge of the box in the last minute.
Arsenal: Lehmann, Lauren, Toure, Campbell, Cole, Parlour,
Vieira (Clichy 75), Edu, Ljungberg, Pires,
Bergkamp (Bentley 84). Subs not used: Keown, Stack, Owusu-Abeyie.
Middlesbrough: Schwarzer, Mills, Riggott, Parnaby, Queudrue,
Mendieta, Downing (Nemeth 73), Boateng, Zenden,
Job (Juninho Paulista 73), Ricketts (Maccarone 73). Subs not used: Davies, Jones.
Sent off: Boateng (86).
Booked: Zenden, Riggott, Parnaby, Boateng.
Referee: M Dean (Wirral).