Aston Villa have taken their summer spending to £40m after finally confirming the signing of Manchester City skipper Richard Dunne.
Republic of Ireland captain Dunne has ended his nine-year spell with City by making a £6m switch from Eastlands.
The Premier League asked for more time to ratify the deal despite Villa starting to submit the relevant documents before 4pm on deadline day - an hour before the transfer window formally closed.
But Villa were always confident Dunne would become their player after passing a medical and agreeing personal terms. The Football Association were also satisfied with the paperwork presented by Villa but needed the approval of the Premier League.
Dunne becomes Villa's second defensive capture of the past 24 hours after Welsh international James Collins signed from West Ham for £5m.
He said: "Richard Dunne is the kind of person we are looking for.''
The 52-times-capped Republic of Ireland international, said: "I'm delighted. It's a great opportunity for me. Aston Villa have improved each season recently, and hopefully I can be part of a squad that can challenge for a Champions League spot.
"With Aston Villa, with the experience they would have gained from last season - they went so close for so long at the top end and the manager has bought in some new players into the squad this year - maybe it might help us go that bit further."
Dunne, who turns 30 on the 21st of this month, was relieved that what proved to be a surprisingly protracted move was finally done and dusted.
"I came on Friday and passed my medical and I thought it would be a straightforward day for me," he told AVTV.
"I think there was just a lot of pressure on a lot of people with so many deals going through, but I'm just really pleased that finally we have it all done."
Dunne's days at Eastlands appeared to be numbered after the arrival of Kolo Toure from Arsenal and then Joleon Lescott from Everton.
Villa started the current campaign with only two experienced centre-backs in Curtis Davies and Carlos Cuellar. The need for new blood became even more pressing after Davies started to suffer more regular recurrences of his long standing shoulder problem and he may need surgery.
O'Neill was forced to blood 19-year-old Ciaran Clark alongside Cuellar in Sunday's 2-0 home success over Fulham.
Villa agreed a fee last week with City for Dunne but the deal dragged on past the weekend because the player wanted to sort out financial issues relating to the remaining three years of his contract. Dunne would have been entitled to a testimonial next summer when he would have completed a decade of service at City.
Villa skipper Stiliyan Petrov said: "He's the captain of Ireland, he's been the captain of Manchester City. You love to see players like that coming to this club.
"Martin Laursen was a big player for us, with his presence and his influence. But he, like Gareth Barry, is now gone and we need to get on without him. The arrival of Dunne will help us to do that.''