The Reds restored their 13-point lead at the top of the Premier League thanks to Sadio Mane's first-half goal at Anfield.
Wolves had an equaliser ruled out shortly after the opener but Jürgen Klopp's side kept the visitors out to secure a hard-fought victory.
"It was [tough]. Wolves are a good team, made it very difficult for us and have good players," Van Dijk told Liverpoolfc.com post-match.
"It's never easy for both sides to play in the circumstances – last week and this week a lot of games, travelling for both sides.
"They made it tough for us and we're obviously very happy that we kept the three points.