Teenage sensation Mason Greenwood and Brazilian midfielder Andreas Pereira replaced Daniel James and Jesse Lingard as The Red Devils made only two changes from their shocking defeat to Watford. Meanwhile, star player Paul Pogba started on the bench again.
However, any thoughts Newcastle manager Steve Bruce may have harboured of completing a league double over his former club had disappeared by half-time.
With his low first-time shot in the 24th minute from Andreas Pereira’s soft pass, Martial drew United level with The Magpies’ goalkeeper Martin Dubravka unable to keep out the strike at the near post.
Newcastle then gifted the hosts a second in the 36th minute when Mason Greenwood put United ahead, profiting off a Fabian Schar blunder to blast a shot past Dubravka from just outside the box.
The visitors fell further behind within five minutes as Marcus Rashford headed an inch-perfect delivery from Aaron Wan-Bissaka to help United lead 3-1 in the match.
United gaffer Ole Gunnar Solskjaer unleashed Pogba right at the start of the second half, with his side in complete ascendancy as Paul Pogba continued his return from injury by playing the entire second half.
This emphatic result lifted Manchester United up to seventh in the table, just four points behind fourth-placed Chelsea.
Scoreline: Manchester United 4- Newcastle United 1
Goalscorers: Matthew Longstaff(16′), Anthony Martial(23′), Mason Greenwood(35′), Marcus Rashford(40′), Anthony Martial(50′)