Manager Steve Staunton got his first competitive victory as the Republic of Ireland secured their anticipated win over San Marino at Lansdowne Road.
Kevin Doyle and Robbie Keane were on target for the Republic
A deflected Andy Reid free-kick, Kevin Doyle's first goal for the Republic and a Robbie Keane strike gave the Irish a 3-0 interval advantage.
Playing at Lansdowne for the last time before redevelopment, Keane added two in the second half for his hat-trick.
He netted a penalty on 57 minutes and then a close-range strike near the end.
The Republic's top scorer, Keane has now got 29 goals from 70 appearances.
It was far from a brilliant performance from Staunton's men against such mediocre opposition, but it gave the fans something to sing about in the rain as they said farewell to their familiar, though dated, old ground.
Ireland's matches now move to Croke Park while Lansdowne undergoes a major redevelopment.
The Republic scored their opener after just six minutes.
From a free-kick just outside the box, Reid's left-foot curler struck Simoncini's head and flew past wrong-footed goalkeeper Federico Valentini.
Reading striker Doyle's big moment came on 23 minutes when he got on the end of Kevin Kilbane's left-flank cross and saw his header go in off the underside of the crossbar.
Kilbane was again the supplier in the 31st minute with Keane coolly side-footing low last keeper Valentini.
Ireland's fourth goal came from a 58th-minute penalty.
Paul McShane was brought down by Simone Bacciocchi and Keane scored from the spot.
Five minutes from time Keane pounced from close-range to become only the seventh player to score a hat-trick for the Republic of Ireland.
The last man to do it was David Connolly against Liechtenstein in May 1997.
Republic of Ireland: Given, Finnan, McShane, Dunne, O'Shea, Carsley, Kilbane, Reid, Duff, Doyle, Keane.
Subs: Henderson, Kelly, Douglas, Elliott, Lee, McGeady, Morrison.
San Marino: Federico Valentini, Bugli, Nicola Albani, Bacciocchi, Davide Simoncini, Vannucci, Carlo Valentini, Andreini, Mariotti, Manuel Marani, Selva.
Subs: Aldo Simoncini, Crescentini, Moretti, Ciacci, Michele Marani, Domeniconi, Bonini.
Referee: Lassin Isaksen (Faroe Islands).