Larsson 26,31,41, Brattbakk 38
Half-time: 4-0 Attendance: 47,194
HENRIK LARSSON is exhausting everyone's supply of superlatives. The Swedish striker certainly left Dunfermline breathless, as he kept up the pace of a remarkable season.
Larsson's second successive hat-trick extended his total to 27 goals, and he created Harald Brattbakk's strike in the four-goal wave that killed this fourth-round tie by half-time.
Brattbakk, however, needs to take lessons from his fellow Scandinavian. He squandered an injury-time penalty after substitute Mark Burchill was brought down.
Dunfermline came to Glasgow focused on the past, not the present. On the two previous occasions they beat Celtic in the Cup, they went on to win it.
Indeed the Premier League's bottom club played with a confidence that belied their current status. Stewart Petrie ought to have ended his driving run in the first minute with a goal, but his weak shot never tested the goalkeeper, Jonathan Gould.
Perhaps Celtic's makeshift pairing of Vidar Riseth and Stephane Mahe, neither a central defender, betrayed a sense of anxiety. The visitors, noted for height and strength, bombarded the box with high balls. Andy Tod's diving header produced a fine stop from Gould, before Celtic cut loose with an astonishing injection of goals.
Larsson broke the deadlock in the 26th minute, timing a run perfectly to meet Tosh McKinlay's deep cross from the corner flag and angling a powerful header into the roof of the net.
Five minutes later, the unstoppable Swede doubled the lead with a penalty. Defender Tod foolishly tugged Jackie McNamara's jersey as he went past him and Larsson thrashed his kick past Lee Butler.
David Graham's diving header could have kept the tie alive soon after but it bobbled inches wide. Celtic duly killed the tie in the 38th minute when Brattbakk hit a fine left-foot drive from 20 yards to finish off Larsson's knock-down.
Larsson, though, was not finished. He galloped on to McNamara's clever pass and, with just Butler to beat, chipped the keeper coolly. Celtic then resisted the temptation to showboat after half-time. Lubomir Moravcik's fierce left-foot shot, and another from Larsson, were genuinely menacing.
Much of the industry owed itself to Paul Lambert, who revelled in his new playmaking role and choreographed everything. Yet even Lambert, with only one goal to his name this season, wanted in on the act and the Scotland midfielder was only denied by the overworked Butler's firm grasp.