Robbie Henshaw will make Rugby World Cup debut in Ireland's Pool D meeting with Italy at the Olympic Stadium on Sunday.
The Connacht centre has recovered from the hamstring injury that saw miss the victories over Canada and Romania, and becomes the final member of Joe Schmidt's 31-man squad to feature in the tournament.
Henshaw will partner Keith Earls in midfield after Jared Payne failed to recover in time from a badly bruised foot, while Simon Zebo continues at full-back as Rob Kearney is given an extra week to recover from a gluteal strain.
Head coach Schimdt has made 11 changes to the team that thumped Romania in front of a World Cup record crowd at Wembley.
Seven of those come in the pack where only Jamie Heaslip remains. Jack McGrath gets the nod ahead of Cian Healy at loosehead, with captain Paul O'Connell set to continue his second row partnership with Iain Henderson.
Jonny Sexton and Connor Murray return at half-back, with Earls switching from wing to outside centre in the absence of Payne.
Tommy Bowe retains his place after scoring two tries against Romania, with Dave Kearney selected on the left wing.
Devin Toner's performance at Wembley sees him preferred to Donnacha Ryan on the bench, where he is joined by Ian Madigan and Luke Fitzgerald.
Meanwhile, Italy welcome back talismanic captain Sergio Parisse from injury for a game they must win to keep alive their hopes of reaching the quarter-finals.
The Azzurri make five changes to the team that scraped past Canada, with No 8 Parisse replacing Samuela Vunisa.
Andrea Manici starts at hooker in place of the injured Leonardo Ghiraldini while flanker Simon Favaro makes his first World Cup start.
Ireland: 15 Simon Zebo, 14 Tommy Bowe, 13 Keith Earls, 12 Robbie Henshaw, 11 Dave Kearney, 10 Jonny Sexton, 9 Connor Murray; 1 Jack McGrath, 2 Rory Best, 3 Mike Ross, 4 Iain Henderson, 5 Paul O'Connell (c), 6. Peter O'Mahony, 7 Sean O'Brien, 8 Jamie Heaslip.
Replacements: 16 Sean Cronin, 17 Cian Healy, 18 Nathan White, 19 Devin Toner, 20 Chris Henry, 21 Eoin Reddan, 22 Ian Madigan, 23 Luke Fitzgerald.
Italy: 15 Luke McLean, 14 Leonardo Sarto, 13 Michele Campagnaro, 12 Gonzalo Garcia, 11 Giovanbattista Venditti, 10 Tomasso Allan, 9 Edoardo Gori; 1 Matias Aguero, 2 Andrea Manici, 3 Lorenzo Cittadini, 4 Quintin Geldenhuys, 5 Josh Furno, 6 Francesco Minto, 7 Simone Favaro, 8 Sergio Parisse (c).
Replacements: 16 Davide Giazzon, 17 Michele Rizzo, 18 Dario Chistolini, 19 Alessandro Zanni, 20 Mauro Bergamasco, 21 Guglielmo Palazzani, 22 Carlo Canna, 23 Tommaso Benvenuti.