The Reds steamrolled a disappointing United side in the first leg of their Europa League last-16 clash.
I just thought it was a disgraceful performance from the Manchester United players
Daniel Sturridge broke the deadlock with a powerful penalty past David De Gea after Nathaniel Clyne was fouled by Memphis Depay.
Brazil international Roberto Firmino extended Liverpool’s lead with 17 minutes remaining to put the Reds in command ahead of the second leg at Old Trafford next week.
Jurgen Klopp’s side finished with 60 per cent possession after 13 shots on targets and 26 tackles during a frenetic north-west derby.
Former Liverpool striker Fowler branded Louis van Gaal’s player a disgrace after their resounding first-leg defeat.
“I was very, very shocked with Manchester United,” Fowler told ITV Sport.
“I think they were disgraceful. Coming here in such a big game and two players could come out with credit – the keeper and Marcus Rashford.
“I just thought it was a disgraceful performance from the Manchester United players.”
Liverpool’s 2-0 win ended a four-game losing streak against Van Gaal’s side in all competitions.
United will host West Ham United in their FA Cup quarter-final at Old Trafford on Sunday afternoon.
The Reds make the return trip to Old Trafford in the Europa League next Thursday night.
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