Dundee were given a harsh lesson in Premiership life as Celtic romped to a 6-0 victory at Parkhead.
Ange Postecoglou’s side had endured a tough start to the season but found their groove against the Dark Blues.
New signing Kyogo Furuhashi was just too good for the visitors with the Japanese striker netting a hat-trick on his league debut.
Tom Rogic and Anthony Ralston would net in the second half on a stormy day at Parkhead.
And in the closing stages things went from bad to worse for Dundee as Jordan Marshall saw red before Odsonne Edouard netted a sixth from the spot.
James McPake made three changes to his side with Cillian Sheridan and Ryan Sweeney making their first Dundee starts while Shaun Byrne returned in midfield.
Celtic, meanwhile, gave Premier League winner Joe Hart and new signing Furuhashi league debuts.
Former Dee Scott Bain joined wantaway Edouard on the bench.
The rain was pouring but couldn’t dampen the mood of the 24,000 home fans inside Celtic Park as they roared the game under way.
Dundee, in their sky blue away kit, knew the first task would be to weather the early storm.
They did start brightly but before long the traffic was heading one way.
There was one let-off from new boy Furuhashi early on, passing up a sitter, before the Japanese showed his quality in front of goal.
His first Premiership strike came in simple fashion as he turned a Liel Abada cross into the net after the Israeli got free down the right.
That came on 20 minutes, five minutes later he had his second.
This time it was Ryan Christie on the left wing doing the damage.
He skinned Christie Elliott before cutting across goal for Furuhashi to slide beyond Legzdins.
Seconds later it was almost a hat-trick only for Legzdins to deny the Japanese at the far post.
Two goals behind and 45 minutes to go, the second-half task was a large one for Dundee to get back into the game.
However, they created their first real opening straight after the restart as Sheridan poked just wide of the post from a long throw.
The challenge, though, got even tougher just seconds later as Christie robbed Elliott inside the area and laid the ball on a plate for Rogic to make it 3-0.
Elliott’s miserable afternoon was brought to an end shortly after as he was replaced by Fin Robertson.
The scoreline may have been beyond them but Dundee almost got one back as McGhee headed just over the bar.
Chances continued to come for Celtic, however, as Furuhashi missed another hat-trick opportunity before grabbing his third on 68 minutes with a lovely flicked finish.
To add to Dundee’s woes the heaven’s opened for the final 20 minutes.
The flow of goals, though, didn’t stop as former Dundee United man Ralston added further salt to the wound with a fifth on 84 minutes.
More pain would come two minutes before the end as Marshall was red carded for dragging down Abada in the area.
Edouard stepped up to finish the job with a sixth goal for Celtic.
Teams
Celtic: Hart, Taylor (Montgomery 72), Starfelt, Furuhashi (Edouard 69), Abada, Turnbull, Christie, Rogic (Forrest 64), McGregor, Ralston, Welsh.
Subs not used: Bain, Bitton, Ajeti, Soro.
Dundee: Legzdins, Elliott (Robertson 52), Sweeney, Ashcroft, Marshall, Byrne, McGhee, Adam (McCowan 60), McGowan, McMullan, Sheridan (Cummings 60).
Subs not used: Lawlor, McDaid, Panter, Wilkie.
Referee: Euan Anderson