Moussa Dembele hit his second hat-trick inside six days as Celtic took another emphatic step towards the treble with a 6-0 William Hill Scottish Cup victory over Inverness.
Dembele had his treble wrapped up before the hour mark of a one-sided fifth-round tie after returning from a knee injury to lead Celtic's second-half comeback against St Johnstone on Sunday.
Mikael Lustig, Kieran Tierney and Scott Brown also got on the scoresheet for Brendan Rodgers' men.
Inverness had contained the runaway league leaders for the opening 20 minutes but they were undone by an accurate lofted pass from Nir Bitton and another impressive piece of penalty-box skill from Lustig.
The Swede, who helped set up Dembele's third goal in Perth with a rabona pass, took Bitton's ball down brilliantly with his right foot before turning and slotting the ball underneath Owain Fon Williams from five yards with his left.
Caley Thistle remain the only team to deny Celtic victory in 30 domestic games this season but they arrived at Parkhead without a Ladbrokes Premiership win in 13 games and they could not find their way back into the game despite starting with two strikers in Henri Anier and Billy McKay.
They resorted to crude tactics and were lucky to keep 11 men on the park as they racked up four bookings in 13 minutes.
Carl Tremarco produced a blatant trip on James Forrest; Ross Draper tripped Brown off the ball right in front of referee Kevin Clancy; Iain Vigurs went in hard and late on Scott Sinclair and Gary Warren brought down Dembele.
There was nothing they could do to stop Dembele doubling Celtic's lead on the stroke of half-time, although Fon Williams should have done better.
The former Fulham striker's effort from a Forrest cutback was straight at Fon Williams, who was dropped for last weekend's draw with Dundee, but the ball squirmed underneath the Welshman's hand and over the line.
Dembele's second came five minutes into the second half after Sinclair turned well on the edge of the box. David Raven stopped him with a slide tackle but the ball fell kindly for Dembele, who slotted into the far corner.
The 20-year-old nodded home nine minutes later after Forrest had beaten Brad McKay and hung a cross straight on to his team-mate's head.
Forrest could have had one himself when he intercepted as McKay waited for Warren's pass to reach him but the winger shot wide from 18 yards.
Inverness rallied but could not trouble Craig Gordon with several efforts on goal and Tierney got in on the scoring in the 86th minute after another assist from Forrest, powering a header home from 12 yards.
Brown made it six in stoppage time when he lashed the ball into the top corner from 18 yards after Sinclair's cutback eventually fell for him.