The Leinster full-back crossed in the 61st minute for the only try of a full-blooded Pool A contest with Leicester in front of 7,000 delirious Dubliners. Leicester, last season's beaten finalists, never came to grips with a passionate Leinster pack, who did not gave an inch.
They were backed up by the impeccable boot of fly-half Alan McGowan, who kicked three out of three penalties and converted the try.
Leicester, unconvincing winners in Dublin last year, had to rely on the boot of their South African fly-half Joel Stransky for their only points but his three penalties from five attempts were not enough to save the English Cup holders.
Victory for the Irish champions puts them back in the hunt for a quarter- final place following their opening-day home defeat by Toulouse.
n Clive Woodward's installation as the new England coach is still subject to negotiation but the Rugby Football Union expects to link him and the manager, Roger Uttley, with the 77 players at Wednesday's squad session.
The RFU will not yet confirm the identities of the management team to succeed former coach Jack Rowell's panel while talks continue, but it has been discussing the terms of Woodward's release from his position on Bath's coaching staff.
Don Rutherford, the RFU rugby director, said: "It's not as easy as in the old days when you simply asked the best man to take on the job and he slipped effortlessly in. Now obligations to clubs and employment conditions make these appointments more complicated."
Fran Cotton, the powerful vice-chairman (playing) of the RFU Management Board, insists the coaching job must be full-time. This gives Woodward no chance of staging his three coaching sessions per week at Bath and watching only them on Saturdays.
The RFU is now two weeks behind schedule, having postponed the announcement of England's World Cup management team last month. Without selectors, Rutherford was forced to invite a huge squad, but further disruption to the build-up to the four Tests before Christmas can be avoided - if Woodward and Uttley can be paraded at Bisham Abbey next week.
n English Rugby Partnership has announced that its chief executive Kim Deshayes is to leave his post at the end of this year. Deshayes, a key player in thrashing out agreement between England's topclubs and the Rugby Football Union following months of argument over running the professional game, will pursue other business interests.