Twigg scored the first ever goal at Tallaght when Rovers beat Sligo back in March 2009, bringing cult hero status.
Fittingly, on his final home appearance after four years at the club, Twigg scored his 19th and 20th goals of the campaign to ensure he’ll finish the league’s top scorer for a third time in four seasons.
The 28-year-old Scot grabbed his first on 18 minutes skipping between two defenders, and rounding keeper Ger Barron to slide it home.
Two minutes later he repeated the trick.
UCD responded within a further two minutes with a goal of the season contender from David McMillan, flicking the ball into the air, turned and firing a stunning dipping volley from 20 yards.
UCD were inches from levelling seven minutes in when Samir Belhout’s low drive was deflected for a corner. But it was the Rovers fans who were on the feet on 75 minutes as Twigg was substituted to a standing ovation.
SHAMROCK ROVERS: Jansson; Sullivan, Oman, Gartland, Powell; Rice, McCormack; Dennehy, McCabe, Greene; Twigg (O’Neill 75).
UCD: Barron; Douglas (Langtry ht), Leahy, Kavanagh, Nangle; Mulhall (McCabe 67), Burke, O’Conor, Benson, Belhout (Lyons 60); McMillan.
Referee: Paul Tuite (Dublin).