An own-goal at the Waterford RSC, created by Jack Byrne in front of Martin O’Neill and Roy Keane, put the hosts ahead on 17 minutes before Italy turned the game around with a brace before the break and another pair in the second half.
The loss leaves Ireland trailing Italy by seven points and needing to beat Slovenia on Monday to have any hope of salvaging second place.
“This Italy team are a serious outfit and they punished us,” said King. “We gave them a run for their money at certain stages but Italy are favourites to win this group and we’ll just have to try bounce back against Slovenia.”
Ireland had a strong penalty claim rebuffed on 13 minutes as Callum O’Dowda looked to have been shoved by Alessio Barreca following a long throw-in from Jack Connors.
It was from another set-piece four minutes later that the lead came. When Byrne whipped in a low free-kick from the left, Rolando Mandragora’s sliced clearance deflected into his own net.
However, the Azzurri soon gained control, scoring two goals in eight minutes, Marco Benassi volleying in the first on 28 minutes.
Ireland’s defence was horribly exposed for the second strike, Valerio Rosseti heading high into the net.
The Italians again caught Ireland napping to sink a third goal. From a swiftly taken free-kick 13 minutes into the second half, Danilo Cataldi teed up left-back Antonio Barreca to nip in and set up Alessio Romagnoli for a simple finish from close range.
To compound an evening of woe for Ireland and Darragh Lenihan, the skipper inadvertently rattled his own net after Romagnoli’s shot struck the post and rebounded off his outstretched leg past Rogers.
D Rogers (Falkirk); B Lenihan (Hull City), G Rea (Luton Town), N Keown (Reading), Connors (Dagenham); D Lenihan (Blackburn Rovers), K O’Connor (Cork City); H Charsley (Everton), J Byrne (SC Cambuur), C O’Dowda (Oxford United); C Wilkinson (Newport County).
B Miele (Shamrock Rovers) for H Charsley, S Hoare (St Patrick’s Athletic) for O’Connor (72 mins), S Maguire (Cork City) for Byrne (85 mins)
G Donnarumma; A Conti, M Caldara, A Romagnoli, A Barreca; D Berardi, D Cataldi, M Benassi, R Mandragora; G Monachello, V Rosseti.
L Garritano for Berardi (65 mins), L Mazzitelli for Cataldi (77 mins), F Ricci for Monachello (86 mins)