Caley Thistle boss Foran had to do without loan defender Jamie McCart, who was unable to play against his parent club, while Carl Tremarco and Jake Mulraney missed out through injury out as skipper Gary Warren, Brad McKay and Billy King came in.Evidence of Inverness’s confidence following their 2-1 home win over Rangers on Friday night was revealed as early as the fourth minute with midfielder Liam Polworth’s speculative attempt from 45 yards which went wide.The home side, though, found themselves relying on some dogged defending as an energetic Celtic took control for a spell, although Hoops keeper Craig Gordon was asked by striker Billy McKay to save a low 20-yard drive in a 19th minute counter-attack.The champions stepped up the pace again. A fine strike by Mackay-Steven from the edge of the box following a Hoops corner was brilliantly parried by Fon Williams for another corner which came to nothing.The pressure on the home side’ penalty area was relentless and the breakthrough eventually came less than three minutes from the break when Sinclair escaped some tight Inverness marking and drove a shot from 25 yards past the helpless Fon Williams for his 17th of the season.The Caley Thistle keeper, however, ended any hope of comeback around 12 seconds after the break when his attempted clearance from a pass back spun into the air to Dembele, who flicked the ball past him and knock in for one of his easiest goals in a fruitful season.Celtic then went for the throat. First Sinclair thrashed a shot high over the bar, then Fon Williams denied Armstrong with a fine save from close range but was beaten at his near post by the former Dundee United midfielder’s wonderful free-kick from 25 yards.The points were safe but Gordon did well to tip a Polworth volley over the bar for an Inverness corner which he gathered with ease.Celtic left-back Kieran Tierney then released Dembele with a raking pass which allowed the 20-year-old Frenchman to chip Fon Williams with unsurprising assuredness, the home side happy to finish with no more damage to their goals-against tally. In what is becoming a stats-fest, Brendan Rodgers’ side went 27 points clear of Aberdeen with their 22nd successive league win which extended their unbeaten domestic run since the start of the season to 33 games.Inverness had dropped back to the bottom of the table on Tuesday night with Hamilton’s surprise 1-0 home win over second-placed Aberdeen and will continue their battle for survival hoping confidence has not been dented too much.Celtic, for their part, face St Mirren in the William Hill Scottish Cup quarter-final on Sunday with their sights firmly on the domestic treble which is becoming more likely by the game.Rodgers could hardly have been more confident on his return to Inverness given his side’s spectacular form and he made two changes to his side with fit-again right-back Mikael Lustig replacing Cristian Gamboa with winger Gary Mackay-Steven in for injured James Forrest. Celtic ensured there would be no second slip-up at Inverness in an almost flawless Ladbrokes Premiership season with a thumping 4-0 win at the Tulloch Caledonian stadium.The only two points the runaway league leaders had dropped in the previous 26 games was in the 2-2 draw against the Highlanders at the same venue last September.However, after attacker Scott Sinclair fired Celtic ahead just before the break, a botched clearance from keeper Owain Fon Williams just seconds into the second-half allowed in-form Hoops striker Moussa Dembele to effectively seal the points with an easy goal.Midfielder Stuart Armstrong added a third with an impressive free-kick before Dembele scored his 11th goal in five games with his 31st of the season.