The 3-1 fifth-round loss to Everton ended a domestic run of 16 unbeaten matches dating back to early November - but I'm hoping it could be a result that gives their hopes of gatecrashing the Premier League's Fantastic Four a real shot in the arm.
O'Neill is working with a 26-man squad at Villa Park, but only 21 first-team players will be realistically considered for the all-important final third of the season which will feature crunch UEFA Cup and league showdowns.
Villa have won fans aplenty with their eye-catching, counter-attacking style of play this season, and I'm sure I'm not alone in hoping they last the pace and secure qualification for next season's Champions League following year after year of the 'Usual Suspects' lining up in Europe's elite competition.
Sorry Arsenal fans, but it's time for a change to the old routine, and if O'Neill's troops - who currently hold a seven-point lead over the Gunners - go on to finish in third or fourth place, it will be fully deserved as they've won more games on the road than Manchester United, Chelsea, Liverpool and Wenger's men, who have so far bagged 20 points away from The Emirates, compared to Villa's 30-point haul from 13 games.
Another reason why O'Neill deserves a huge pat on the back is that his team is made in England, with the Midlanders supplying seven of the 23 players Fabio Capello named for last week's friendly with Spain.
The likes of James Milner, Curtis Davies, Ashley Young, Gabriel Agbonlahor, Luke Young, Steve Sidwell and Gareth Barry have flourished under the Irishman's guidance, with most of them now established international stars.
And the shrewd capture of Emile Heskey in January's transfer window should ensure the Villans don't run out of steam when they enter the final bend.
Villa may have had their FA Cup dreams shattered by Everton, but they're still gunning for UEFA Cup glory and are on a 13-game unbeaten run in the Premier League, having last tasted league defeat against Middlesbrough at home on November 9.
Many pundits are saying this week could define their season, with Wednesday's home game against CSKA Moscow followed by the visit of Chelsea to Villa Park on Saturday.
But I disagree and would urge Villa fans not to hit the panic button if both games end in defeat.
The Gunners may have a 29-man squad to call upon, but are still juggling FA Cup and Champions League balls alongside their top-flight exertions.
In the 11 league games played between March 1 and May 11 last season, Villa picked up 13 points, while Arsenal amassed 19 points.
I'd fancy them to bank more points this time around due to their greater squad depth - but even if they can replicate that haul it would leave the Gunners with a mountain to climb, and Wenger's faith in youth over experience could ultimately come back to haunt him.