The Dutchman, signed from Bayern Munich on transfer deadline day, tapped in a rebound from close range for the opener before Diogo Jota netted in added time to ensure Liverpool remain top of Group E with maximum points.
Gravenberch was a regular for Ajax, making 89 appearances in his last two title-winning seasons with the Dutch club, but had limited game time after signing for Bayern in 2022, with most of his appearances coming off the bench.
Since joining Liverpool, Gravenberch has started just three games, picking up assists in wins over Leicester City and LASK.
"I think it's really obvious how good he is, what a talent he is," Klopp told reporters on Thursday. "He's enjoying the situation, enjoying himself, that's very important, (he) gets step by step all the confidence back, that's really cool to see.
"We wanted to give him 90 minutes, but then we saw now he dropped a little bit and didn't want to go there (with) any risks so that's why we brought on (Dominik Szoboszlai) for a few minutes.
"Everything goes in the right direction, that's really helpful."
Speaking to TNT Sports, Gravenberch said his goal was the "easiest" of his career, adding: "It doesn't matter – a goal is a goal.
"When you give a player minutes, you get confidence and I think that's it."
Liverpool next travel to Brighton & Hove Albion in the Premier League on Sunday.
