Arsenal reached the Carling Cup last eight by ending Reading's 23-game unbeaten run in convincing fashion.
Jose Antonio Reyes sprung the offside trap to round Graham Stack and put Arsenal ahead after 12 minutes.
Dave Kitson had chances for Reading, but Robin van Persie struck the crucial blow when he fired home from 18 yards three minutes before the interval.
And a revamped Arsenal side added a third after 65 minutes when substitute Arturo Lupoli finished in style.
Reading showed plenty of promise in their display, but in sharp contrast to Arsenal, they could not find the finish to match their approach play.
Arsenal maintained their policy of fielding a youthful side in the Carling Cup - but they still had too much attacking flair for Steve Coppell's side as they established control in the first 45 minutes.
Reyes was one of the more experienced Arsenal players on display, and he was on target as the Gunners took the lead after 12 minutes.
Dave Kitson had a half-chance for Reading, but they had no answer to a trademark Arsenal strike.
Quincy Owusu-Abeyie slipped a pass in for Reyes, who ran into the area and skipped around Stack to score from an angle.
Owusu-Abeyie was a constant threat, and he almost created a second for Van Persie, but his drive was turned aside by Stack.
Reading were not out of contention, however, and Manual Almunia did well to save from Leroy Lita after a poor clearance by Philippe Senderos.
Kitson then had a good chance to equalise when Graeme Murty found him in space, but he could only direct his powerful header straight at Almunia.
It proved a pivotal moment, as Arsenal sprang forward to add their second three minutes before the interval.
Reyes laid the ball into the path of Van Persie, and he drilled home a comprehensive finish from the edge of the area.
Arsenal were now in total command, and they added a third through Lupoli after 65 minutes.
He had replaced Van Persie, and after Kerrea Gilbert produced a stunning save from Stack, Lupoli made an immediate impact with a good finish for the third.
Reading defender Ibrahima Sonko lost control of a long pass and Lupoli was in quickly to round Stack and score in the unguarded net.
As time ran out and Arsenal cruised to victory, Reading suffered another blow when injured goalkeeper Stack was replaced by Marcus Hahnemann.
Arsenal manager Arsene Wenger:
"Overall I'm very pleased for the boys, because it's great experience to be in there.
"They are all under 23, some are 18, some are 22. Overall they have a great spirit - I rate them all. But it's very difficult to say now who will make a big career at Arsenal - they all look to have a chance.
"I think Reading are a good team. They have good team play, a very mobile team, they are tuned in together- there is a good understanding. And they have a way to play that looks fluent and dangerous - for me it's a good side."
Reading manager Steve Coppell:
"I'm not going to draw any grand conclusions from that. It was a busman's holiday for us - a day to experience a wonderful old stadium against a tremendously strong club.
"I wanted us to try and have a go. I wasn't overly concerned with the result. I just wanted us to play well and in sections we did, but our finishing wasn't at its best.
"With £23m of talent starting the game, even with a secondary unit, they still had the decisive cutting edge. The second goal was a sucker punch."
Arsenal: Almunia, Eboue, Larsson, Senderos, Gilbert, Muamba, Djourou, Flamini, Reyes, Owusu-Abeyie, Van Persie. Subs: Cygan, Poom, Bendtner, Connolly, Lupoli.
Reading: Stack, Murty, Ingimarsson, Sonko, Shorey, Oster, Harper, Sidwell, Hunt, Kitson, Lita. Subs: Hahnemann, Little, Convey, Doyle, Makin.
Referee: L Mason (Lancashire)