The Dutchman, linked with a move to Wolfsburg this week, struck in first-half injury time before promptly being substituted.
Liverpool should have won more convincingly but Joe Cole's miserable week continued as he had a second-half penalty saved.
New boy Christian Poulsen made his debut for the Reds.
While Mario Balotelli scored in his debut as Manchester City beat Timisoara 1-0 in their Europa League play-off first leg in Romania.
The former Inter Milan striker's registration was only received by UEFA on deadline day.
Balotelli responded by stepping off the bench to sweep the ball home after 72 minutes to put City in the driving seat with the second leg to come at Eastlands next Thursday.
Aston Villa drew 1-1 against Rapid Vienna in the first leg of their tie.
Caretaker boss Kevin MacDonald gave youth a chance as he looked to justify claims from some that he should be given the role vacated by Martin O'Neill on a full-time basis.
Marc Albrighton built on his impressive showing in their Premier League opener against West Ham with an assist for fellow youngster Barry Bannan to net early on in the first half.
However, Atdhe Nuhiu equalised for Rapid and they could well have won it had they not wasted several good chances to head to Villa Park with the lead.