Delph highlighted the sheer confidence which currently exists in Villa's squad and the teenager capped a brilliant display by scoring his first goal since his move from Leeds.
Brighton had their moments after going behind to an early strike from Nathan Delfouneso.
Tommy Elphick equalised but two second-half goals from Ashley Young and Delph sealed their fate despite a late effort from Nicky Forster.
It was hardly surprising that following their high scoring 6-4 Carling Cup success over Blackburn in midweek, Villa made six changes to face the League One side.
Manager Martin O'Neill, who admitted he could not believe his eyes as he watched the 10-goal bonanza, included Ashley Young in striking role and also made the England player captain for the day.
Young responded with a shot on target in the opening 30 seconds which Michael Kuipers ominously failed to hold.
It was Young who set up Marc Albrighton, who outstripped Jim McNulty before sliding a low pass into the middle for teenage striker Delfouneso to slip the ball into the net from close range in the sixth minute.
Unfortunately Albrighton injured himself in the build up to the goal and had to be replaced by England international, James Milner - Villa's star of the moment.
Roared on by their 6,000 travelling fans, Brighton attempted to get back into the game but there was a big difference in class, although Forster should have done better with a rare goalscoring opportunity.
Brighton slowly lost their early nervousness and began to play with more confidence as Alan Navarro organised the midfield and set up several promising attacks.
One in particular raised Brighton's hopes of an equaliser but Glenn Murray flipped his effort over the bar.
Three minutes before the break Brighton were back on level terms. Elliott Bennett's corner found Murray and the ball bounced down to Elphick to slide the ball past Brad Guzan.
As in the first half, Villa were quickly out of the traps and once again Brighton's defence was exposed by the skill factor of the Midlanders three England internationals, Milner, Stewart Downing and Ashley Young.
It was Milner, playing on the left, put Downing in possession with one of his astute passes. Downing's long cross found the unmarked Ashley Young to head home.
This goal was a tremendous setback for the south coast club. They were slowly out-gunned by Villa's class which was emphasised by their third goal from teenager Delph in the 63rd minute.
But what must have pleased manager O'Neill was the way Delph notched his first goal for Villa.
Milner again created the opening as Delph waltzed down the middle and calmly jinked his way past Kuipers to slot the ball home.
Young Delfouneso then hit the post before Forster picked up a Murray pass to score in the 87th minute to produce a rousing finish.