The two rivals drew 2-2 at United's old training ground, The Cliff Training Centre, with Timossi Andersson opening the scoring after 16 minutes. Aidan Barlow scored an 89th-minute penalty for the home side after Liverpool had come from behind to take the lead midway through the second half.
United trialist scores in first game
The 16-year-old has been at United this week, leaving Swedish side Helsingborgs IF. He has previously been on trial at Bayern Munich, in 2016. Helsingborgs IF manager Per-Ola Ljung said "we can confirm that he is going to Manchester," ahead of this week.
Timossi Andersson had to wait for a gap in his school calendar, Ljung and the players' parents revealed. "United have for some time wanted to meet Timossi Andersson, but it was important to not let it come between school," Ljung said.
"We thought it was appropriate to do it now so he does not miss anything in school."
Andersson has played for HIF first team
Ljung gave Timossi Andersson his debut with the Swedish side in mid-February, playing the full 90 minutes in a Swedish Cup game against Brommapojkarna.
Andersson said ahead of his trial at United that it is "great that you can go to the team that you have dreamed about since you were little."
"I may not be as nervous as last time [at Bayern]. Now I have a little known of how it is to be in a big club again. Then one is a little easier.
"I'll do as well as I can, then we will see," he is quoted as saying by Expressen.
United have taken on a number of trialists in recent weeks as their recruitment drive for the academy continues. Two Polish goalkeepers, Jakub Ojrzyński and Nicholas Bieganski, both 14, recently had trials with the Reds. This may be due to the recent addition of ex-Legia Warsaw scout Radoslaw Kurcharski to United's scouting set-up.