The two sides met in the Europa League on Thursday evening, as Jurgen Klopp returned to his former club for the first time.
The German boss sprung a surprise before the game, opting to name Origi as his centre forward ahead of Daniel Sturridge.
It proved be an inspired decision as the Belgian put in a top display, scoring his side’s goal in the eventual 1-1 draw.
Hargreaves was one of those who was impressed by the way the youngster performed, saying the young striker was exceptional.
“I thought he was exceptional,” he told BT Sport.
“For a young player to play the way he did, he was the perfect centre forward. Not only in terms of scoring the goal, but also leading the line.”
“He was Liverpool’s best player on the day, not only because of his goal. He was exceptional.”
Origi will now be keen to build on this impressive display between now and the end of the season.
There is certainly a chance up front, with Daniel Sturridge, who is the first choice striker at the club, having struggled for his best form in recent weeks.
Compatriot Christian Benteke is also far out of contention, meaning there is an opportunity for the Belgian youngster to come in and make his mark for a starting spot in future.