The Reds produced an impressive comeback win at London Stadium to claim the spoils, their third consecutive top-flight success.
Gakpo levelled for Jürgen Klopp's men in the opening period following Lucas Paqueta's earlier strike, before Joel Matip's powerful second-half header made the all-important difference.
The No.18's long-range effort saw him record his sixth goal since joining the Anfield ranks in January, and he was left impressed by the battling spirit on display.
"I'm really pleased," Gakpo told Liverpoolfc.com post-match. "I think it was a good game from our side.
"We could have scored more but at the end the win was really important and I'm really happy.
"I think you have to stay sharp for 90 minutes [against West Ham] because it's only one moment they can counter and then they get a goal. But we did really well defensively - at the end they scored one and we scored two. We did great."
On recording back-to-back victories away from home, he added: "I've not been here so long, so I don't know how it felt before, but I think we're getting on the right track.
"There's still lots to improve, but we'll keep working hard and try to keep winning away from home."
The Reds now turn their attention to the hosting of Tottenham Hotspur on home soil at Anfield on Sunday afternoon.
Ahead of the final midweek fixtures, Liverpool moved to within six points of the top four positions as they continue to try to assert pressure on the teams above them.
Gakpo concluded: "I think this three points were really important with the weekend upcoming so we can get real pressure on it [the top four]. It's up to us to prove again this weekend what we are capable of."