As well as O’Neill’s treble, Lloyd Dawes netted his first double since returning with Worthing cruising to a 5-0 victory over division-lower Ryman League South opponents Bridges.
Worthing were much-changed for the first-round encounter, with six changes made from Saturday’s 4-1 home league defeat at the hands of Wingate & Finchley.
Joint-management duo of Gary Elphick and Jon Meeney handed youth a chance in the League Cup competition as three players aged 18 or under started the clash.
Worthing made a decent start and found themselves in front with seven minutes on the clock.
Reis Stanislaus dispossessed Jack Rollings, before his cross was headed home by an unmarked O’Neill from close range.
Worthing continued to apply press on Bridges’ backline and Dawes so nearly made it two 13 minutes later. His free-kick was expertly curled over the wall but went agonisingly over.
O’Neill then should have had his second with a header once again a minute later. This time Steve Metcalf whipped in a cross, though, a free O’Neill well over.
Devon Fender almost levelled things up with a smart effort on 26 minutes.
Dawes lost the ball with Tim Cook rampaging forward, his cross found Fender with his clipped effort bouncing back off the crossbar.
Worthing took full advantage of that miss just a minute later. Metcalf’s whipped cross found another unmarked O’Neill who slotted into the bottom corner.
With time running out in the opening 45 minutes Dawes got his first goal since making a return to Worthing.
Will Hendon pinged a ball into the winger, his first touch was controlled on his thigh before lashing home a volley to make it three.
Fender was causing Worthing’s backline some problems early in the second. First less than a minute after the break, he pulled a strike just wide.
Then decent link-up between him and Cook saw the former crash a strike towards goal but Jack Fagan was equal to his effort.
Stanislaus thought he had hit a fourth for Worthing on the hour mark. Dawes’ pass found Luke Brodie, whose ball was tapped home by the forward but his strike was ruled out for offside.
Substitute Mitch Casselman nearly gave him side some hope 20 minutes from time, Hakeem’s Adelakun cross was flicked just over off the head of Casselman.
Worthing were handed a chance to add a fourth as, after rounding Martin Grant, Dawes was hauled with a spot-kick awarded.
Following a brief discussion with Dawes, O’Neill took the ball and thundered home the penalty to complete his hat-trick eight minutes from the end.
Even more gloss was added to the scoreline two minutes later, when Hendon’s cutback found Dawes and he side-footed past Grant as Worthing cruised to a 5-0 victory.
WORTHING: Fagan; Hendon, Heath, Watson, Metcalf; Axell, Edwards; Dawes, O’Neill, Brodie; Stanislaus. Subs: Wills (Axell), Newhouse (Brodie), Punter, Hallard (Edwards), Banks.