The Tigers' latest GUINNESS PREMIERSHIP title arrived just seven days before they tackle Leinster in this season's Heineken Cup final at Murrayfield.
And It was Jordan Crane, whose penalty strike enabled Leicester to beat Cardiff Blues in a Heineken Cup semi-final shootout two weeks ago, who saw Leicester home with a 62nd minute try.
Scrum-half Julien Dupuy's conversion and penalty completed their scoring for the side who were contesting their fifth straight GUINNESS PREMIERSHIP final appearance, having lost the last four.
Irish's points came form a Peter Hewat drop-goal and two Delon Armitage penalties - they finished short.
Irish might have played much of the rugby, but they floundered on a Leicester side used to winning, and that experience proved vital.
Irish took the field aiming to become only the sixth club to be crowned English champions, after Leicester, Bath, Wasps, Newcastle and Sale Sharks. And it was they who made an immediate statement of intent.
The Tigers could be excused for seeking identity with unfamiliar sky blue jerseys, and Hewat dropped a goal after 20 seconds to hoist Irish ahead.
Hewat's 45-metre strike served Leicester with immediate intent of Irish ambition, and there was no obvious sign of Leicester asserting any authority.
Dupuy though, levelled the scoreline with an 18th-minute penalty in what could be his penultimate game for Tigers before a possible return to France next season.
But Irish were not to be distracted, gaining a penalty chance when Tigers lock Ben Kay infringed, yet Hewat's seemingly straightforward penalty attempt hit the post.
The game lacked structure, and with the scoreline locked at 3-3, both sides looked to gain an interval advantage by producing an overdue amount of attacking flair.
Crane was sin-binned as the interval approached, yet Irish could not take advantage and a dismal half ended all square.
Armitage booted Irish three points clear on 49 minutes with a penalty, but there remained little to chose between the two teams.
It took an intervention by Crane - from close range - to hoist Leicester ahead, when he stretched over, and Dupuy's conversion made it 10-6.
Armitage booted a 50-metre penalty eight minutes from time that narrowed the gap to one point, but Leicester prevailed.