The fullback admitted it was no more than the youngster deserved to net the only goal of the game.
"We were delighted for Raheem to score his first goal and he deserved it," Johnson told liverpoolfc.com.
"He just takes everything in his stride and is always willing to learn. He has got fantastic attributes and I'm pretty sure and confident that this won't be his last goal in the Premier League that's for sure.
"He is a confident lad every day in training and a good lad as well. He is learning quickly."