Both Mathias and Christian Nørgaard started at the MCH Arena in Herning as Denmark made it two from two in qualifying in fine fashion.
Kasper Dolberg's penalty, a double from Mikkel Damsgaard and Jens Stryger Larsen's effort had Denmark four up before Mathias steered home his maiden international goal seven minutes before the break. Dolberg then made it 6-0 three minutes after the restart.
Christian's third international appearance ended with 25 minutes to play while Mathias played 78 minutes on his fifth senior outing.
The final ten minutes saw two more Danish goals through Robert Skov and Marcus Ingvartsen as Kasper Hjulmand's men climbed to the top of Group F with their record qualifying win.
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On Wednesday night, The Danes face their toughest test of qualifying with a trip to Austria, kick-off 7.45pm. Henrik Dalsgaard will not be involved on Wednesday after he was released by the Danish FA to return to Brentford.
The other action on Sunday night saw Marcus Forss remain an unused substitute as Finland netted an 89th minute penalty to take a point from their trip to Ukraine.
Júnior Moraes put the home side ahead with ten minutes to play but Vitaliy Mykolenko hauled down Teemu Pukki to give away a last minute penalty. The Ukraine defender was shown a straight red with Pukki picking himself up to fire home from the spot.
The point keeps Finland unbeaten in Group D with two points from their opening two matches.
Wednesday night sees The Finns head to St Gallen to take on Switzerland in a friendly match as Marcus looks to earn his fourth full cap.