Van Dijk's header on the hour mark was enough for the 1-0 win.
"A great win," Van Dijk told TNT Sports post-match. "Hard work on a very, very interesting, difficult pitch. Pleased with the three points. Recover and go again on the weekend.
"To come here, to play like we did today, a well-deserved three points. A great game, so we'll take it and move on.
"I think they showed this season how difficult it is to beat them. A lot of credit to them, it's a very hard-working team. With their fans behind them, it makes it a good atmosphere over here.
"It's good to come here and for us to win and keep the clean sheet. A good night for us."
He added, "We have to try to keep building, try to stay fit as well and stay confident and keep improving. Today was a great step forward in terms of our performance with and without the ball.
"Now it's just recover and we play on Saturday at eight o'clock again against Brighton, who are a very difficult team to beat.
"So, we need everyone, we need our fans, we need everyone who wants the best for us in order to get that job done. Now it's time to recover."