There was also another promising display from 21-year-old Nathaniel Phillips, who played nearly the full 90 minutes at centre-back, and a nice moment midway through the second half when Loris Karius, whose errors contributed to Liverpool's defeat in last season's Champions League final, replaced Alisson to huge cheers from the home crowd.
The "keeper made two costly blunders in the Champions League final as his side lost to Real Madrid, although it was later revealed he suffered a concussion moments prior to his first mistake after Sergio Ramos" knee collided with his head.
The signing of Alisson from Roma in a world record fee for a goalkeeper was the latest blow to Karius' time at Anfield, but the move will have taken some of the pressure off of him.
Since Jurgen Klopp's men made May's Champions League final and finished fourth in the Premier League, the Reds have splurged in the region of £160million on Fabinho, Naby Keita, Xherdan Shaqiri and Alisson.
"I was not surprised, to be honest, but as a human being I was hoping for it, that it would be like this".
Jürgen Klopp was delighted to see Danny Ings back in action for Liverpool but admitted the striker's options are "open".
The Red Devils' legend told Express UK on Thursday that United lack quality, adding that, "When you look at Manchester City, possibly Liverpool, I don't think they [United] have the quality of those two teams at the minute". Is it possible being different in a really hard world? I really liked his pre-season.
"It helps not only Loris, but Alisson as well that you can see this very special place".