Brendan Rodgers urged Celtic to rise to the challenge of taking on the world's best in the Champions League after sweeping aside Hearts 4-1 on Sunday to restore a seven-point lead atop the Scottish Premiership.
Three of the Hoops' Japanese contingent were on target as Daizen Maeda, Kyogo Furuhashi and Tomoki Iwata struck after Matt O'Riley fired the visitors into an early lead.
After a slow start to Rodgers' second spell in charge, Celtic are again beginning to dominate domestically.
But the Scottish champions face a big step up in class when they aim to end a six-year drought without a Champions League win against Atletico Madrid on Wednesday.
Celtic have lost their opening two Champions League group games to Feyenoord and Lazio, with another defeat likely to prove fatal to any chance of progressing to the last 16.
"Wednesday will be a great challenge and we want to make it really difficult," said Rodgers.
"We want play the best teams in the world. We don't have to be the best team in the world, but we want to be able to take them on."
O'Riley's fine form to start the season saw him earn a first senior international call-up by Denmark last week.
The midfielder continued his scoring streak in style by cushioning home Luis Palma's pass on the volley for his sixth goal in nine league games after just four minutes.
Hearts had cut the allocation of tickets to travelling Celtic fans in the hope that a more intimidating atmosphere could inspire a first win over the Hoops since 2021.
However, many of the home support had left before the hour mark after an insipid performance by Steven Naismith's men.
"Coming to grounds like this is when you find out if you're a good team or not because you will have difficult moments," added Rodgers.
"But the players dealt with it really well. It's as quiet as I've heard it here."
Maeda had a simple task to tap home Reo Hatate's powerful cross to double the visitors' lead on 23 minutes.
Hatate then missed a penalty at the start of the second half as his spot-kick came back off the post.
But he made amends with an audacious flick that opened up the Hearts defence moments later and led to Kyogo sweeping home his sixth goal of the season.
Hearts captain Lawrence Shankland ended his eight-game goal drought with a sublime finish off the inside of the post.
However, Celtic quickly restored their three-goal cushion when Iwata smashed home his first goal for the club after a goalmouth scramble.
Defeat leaves Hearts still in fourth, four points adrift of third-placed St Mirren.
🥰 Tomoki feeling the love from his teammates after scoring his first Celtic goal! #HEACEL | #cinchPrem | #COYBIG🍀 pic.twitter.com/QIe3f0q1bY
— Celtic Football Club (@CelticFC) October 22, 2023