Ireland's skipper and record goalscorer bagged goals 27, 28 and 29 in 70 caps as his side secured three vital points in European Championship 2008 qualifying.
This was the last football international at the famous old stadium - home of football and rugby union - as work is due to start next year on a £260million, 50,000 all-seater venue to be built in its place.
As expected, Ireland were always on top and scored early via Andy Reid's deflected free-kick. Kevin Doyle made it 2-0 after 23 minutes and Robbie's treble followed after 31, 57 (a penalty) and 85 minutes.
The Republic will now move to the impressive Croke Park Stadium in Dublin with the first Euro 2008 qualifier against Wales on March 24.
Paul Robinson played the full 90 minutes and was our only player on duty as England drew 1-1 against Holland in the Amsterdam ArenA. Wayne Rooney fired England ahead in the first half but Robbo's hopes of another international clean sheet were dashed when Rafael van der Vaart volleyed home four minutes from time. Michael Dawson and Jermain Defoe were unused substitutes.
Robbie Keane couldn't have dreamt of a better send off for Lansdowne Road as he scored his first hat-trick in the Republic of Ireland's 5-0 drubbing of San Marino on Wednesday night.