Liverpool left Old Trafford empty handed as the race for second place shifted very much towards Manchester United after a Marcus Rashford brace inspired Jose Mourinho's side to all three points on Saturday.
Reds defender Virgil van Dijk admits he was left 'frustrated' by Liverpool's inability to break down United despite having the majority of possession for large periods of the game.
Liverpool found themselves two goals down at half-time after two goal-kicks that were won superbly by Romelu Lukaku were twice punished by Rashford.
Jürgen Klopp's side responded in the second period, pulling one back by forcing Eric Bailly to put through his own net just past the hour mark.
However, the Reds failed to take anything from the game with the side still yet to see victory at Old Trafford since 2014.
Two identical goals cost Reds on the day
The Reds conceded both their goals in almost identical positions as twice Dejan Lovren was bullied off the ball by Lukaku and Rashford made Klopp's team pay for their mistakes as he took both his goals superbly.
When asked about his feelings at the final whistle by Sport1, Van Dijk admits he was "frustrated."
"Obviously to concede two almost identical goals was frustrating and it was difficult to break them down today because they sat back waiting for the counter-attack.
"Unfortunately, we couldn't break them down," the defender said.
"First of all, we don't need to concede the two goals in the first half; for the rest, it was difficult to break them down, they sit and hope for the best on the break.
"We needed to try to break them down but it wasn't good enough."
The result left Liverpool five points behind their bitter rivals and Tottenham's 4-1 win over Bournemouth yesterday meant that the Lillywhites leapfrogged Klopp's side leaving them in fourth place.
However, Van Dijk doesn't believe the setback will prove fatal to the Reds' top-four hopes as Liverpool turn their attention to the weekend when they host Watford at Anfield in a Premier League clash.
He added: "There are plenty of games left. Today was a big one but we need to move on and look ahead - it starts next week."