Hearts looked like spoiling Celtic's title party as the home side failed to turn their chances and domination into goals in a goalless first-half at Parkhead.
Eight days after winning the championship, Double-winning Celtic will finally be presented with the SPL trophy after the game.
It was still a day to savour for the green and white army to enjoy with the players and O'Neill opted to name his strongest side available despite the league being sewn up.
Henrik Larsson, for one, was in no mood to be rested as he stood two goals away from Brian McClair's SPL 14-year record of 35 after breaking Charlie Nicholas' post-war club milestone.
O'Neill made three changes from the side which beat Dundee United in the Scottish Cup semi-final, with Neil Lennon being allowed to attend his grandmother's funeral, Chris Sutton injured and Lubo Moravcik on the bench.
Into the side came Jackie McNamara, Colin Healy and Tommy Johnson, whose goal clinched the title.
The rain had threatened to dampen the spirits and Hearts were also determined to gatecrash the party and with their eyes on a Uefa Cup place it ensured that this would be anything but a meaningless end-of-season kickabout.
Celtic started confidently and Didier Agathe, in an usual left-wing position, sent a fierce right foot drive crashing against the upright after four minutes, although the linesman had spotted an offside.
McNamara took up a role on the right and his centre in the ninth minute should have produced a better finish from Alan Thompson, who headed wide of the mark.
Johnson then saw glory in the 15th minute when he attempted an adventurous long-range effort which flew just wide of Antti Niemi's left post with the former Rangers man frantically scurrying across the face of his goal.
But Hearts almost silenced the home crowd a minute later when Celtic were caught upfield.
Colin Cameron broke down the left before finding Gary Wales, who squared to Steven Boyack, but fortunately for the champions Joos Valgaeren made a saving block to deny the visitors.
The home side continued to dominate possession, but were showing a rare lack of conviction in front of the Hearts goal.
Record-breaking Larsson almost bagged the opener in the 25th minute when he took Johnson's through-ball in his stride, but Niemi somehow managed to keep the ball out with his feet.
Moments later and Johnson connected cleanly with Thompson's inswinging corner, but blazed his header just over the crossbar.
Hearts were hanging on and Niemi made a meal of Agathe's right foot shot and he was fortunate his punch out was not picked up by a Celtic player.
Niemi, however, made amends by first claiming another effort from Agathe before saving from Thompson, who should have done better after McNamara had hooked the ball across goal.
But as Celtic committed more men into attack they looked liable to making mistakes at the back and Wales gave them a scare in the 38th minute when he lobbed over the crossbar.