United had faced criticism after an unconvincing 2-0 victory over a depleted Perth Glory on the weekend.
In a much-needed tonic, the Red Devils clinically dismantled Leeds,
who have high hopes of returning to the English Premier League for the
first time since 2004.
Pogba, who has been linked with a move to Juventus and Real Madrid,
starred in United's dominant first-half and was part of a pretty chain
of passing to set up 17-year-old Mason Greenwood's first senior goal in
the seventh minute.
Moments later, a powerful strike from the French midfielder was well saved by goalkeeper Kiko Casilla.
But it was only a matter of time before United broke through with a
moment of magic in the 27th minute from Marcus Rashford, a livewire in
the first half.
After a wondrous dribble past the lead-foot defence, the 21-year-old expertly tapped it past Casilla.
Manager Ole Gunnar Solskjaer changed his entire lineup at half-time in a repeat of Saturday's match against Perth.
United continued to dictate, with Phil Jones scoring a thumping header from a corner kick in the 51st minute.
Anthony Martial rounded out a spectacular performance in the 68th
minute by converting a penalty after Tahith Chong was taken down in the
The first clash in eight years between the one-time bitter enemies
fizzled out, but a near capacity Perth Stadium crowd of 55 000
underlined the rivalry's stature.
Romelu Lukaku was once again absent fuelling speculation he had been
dropped from the squad amid reports he was close to securing a move to
United said the Belgian suffered a knock at training.
Illness kept out goalkeeper David de Gea, who is reportedly close to
signing a new five-year deal with United in excess of £350 000 a week.
United will have further pre-season games against Inter Milan in
Singapore on July 20 and Tottenham in Shanghai on July 25, while Leeds
will head to Sydney to face Western Sydney Wanderers.