Last season's beaten finalists have their sights set on another trip to Wembley and made it three straight wins courtesy of McAnuff's second and third goals of the campaign.
The winger's deadly double, and a late own-goal from Adam El-Abd, condemned Gus Poyet's Brighton, who were the early-season pacesetters, to a third consecutive defeat.
The Seagulls improved after the break but squandered a host of chances with Billy Paynter and Craig Mackail-Smith the chief culprits.
Reading threatened from the first whistle with Casper Ankergren keeping out Jem Karacan's deflected shot and Lewis Dunk clearing a close-range effort from Jimmy Kebe.
Brighton's first chance fell to defender El-Abd, whose shot was too close to Royals keeper Adam Federici.
But Reading went ahead in the 17th minute when Kebe outstripped Brighton veteran Mauricio Taricco and swung in a cross to the centre of the area where McAnuff was on hand to sweep the ball past Ankergren.
The hosts almost doubled their lead three minutes later from a carbon-copy move but this time Mikele Leigertwood could not match McAnuff's finish as his shot flew wide.
Brighton came close to a leveller when Taricco's cross found El-Abd but the full-back's attempted lob came down on top of Federici's goal.
But instead they found themselves two down on the stroke of half-time, when McAnuff collected Andy Griffin's pass, cut inside El-Abd and fired a low shot past Ankergren and into the net.
Poyet threw on Leeds loanee Paynter after the break and the striker, who has yet to find the net for Brighton, spurned a good chance to pull one back when he volleyed Craig Noone's cross over the top.
The Seagulls thought they should have had a penalty moments later when Mackail-Smith was bundled over by Griffin but referee Simon Hooper was not interested.
Brighton were building up a head of steam and Federici was called into action again when he kept out Ryan Harley's shot and a header from Dunk.
Mackail-Smith then had two wonderful chances to make Reading sweat, but he took an air-shot in front of goal and then prodded Noone's inviting cross the wrong side of the post.
And Brighton's misery was complete a minute from time when the luckless El-Abd, attempting to clear Kebe's cross, succeeded only in turning the ball past Ankergren and into his own net.