For Newcastle, it rounded off a fantastic week that had already seen them beat Leicester City 4-0 and reach the semi-finals of the Carabao Cup with a 3-1 success over Brentford.
Isak's hat-trick takes him to 10 Premier League goals this season, only three behind the top scorers – Liverpool's Mohamed Salah and Manchester City's Erling Haaland are on 13 apiece.
The hosts had come into this match after a 94th-minute winner in a 2-1 victory at Wolves, only their second win of the campaign in their return to the Premier League following back-to-back promotions.
That side and the one on Saturday included six players that had been with the team two seasons ago in League One but in truth, they were completely outplayed by a rampant Newcastle.
The only surprise was that it was only four goals for the visitors as they could, and probably should, have had more.
Sandro Tonali curled just over and Gordon, the wrong side of a home defender, had a free header but headed it down into the ground and it bounced up and over Muric's goal.
Isak wasted a one-on-one chance before being gifted his second - Newcastle's third - which killed the game as a contest.
Ipswich, without suspended top goalscorer Liam Delap, created very little and rarely tested Martin Dubravka in the away goal. The hosts' only efforts of note saw Cajuste, Sammie Szmodics and Ali Al-Hamadi fire over on a miserable day for the home supporters.
It will not get any easier for Town either as they play at Arsenal on 27 December before a home game against Chelsea three days' later.
Meanwhile, Newcastle, who played in the Champions League last season but missed out on European qualification for the 2024-25 campaign, secured one of their easiest wins of the campaign.