Jurgen Klopp claimed Liverpool were wrongly denied a winning start to the Premier League season as Watford snatched a controversial last-gasp equaliser in a dramatic 3-3 draw on Saturday.
Reds boss Klopp was furious that Miguel Britos wasn't ruled offside when the Watford defender poked home from on the goal-line after Richarlison's shot was pushed onto the crossbar by Liverpool goalkeeper Simon Mignolet.
Britos's stoppage-time strike capped a rollercoaster encounter at Vicarage Road, which saw Liverpool forced to settle for a point despite twice come from behind to take a 3-2 lead.
"We were unlucky in the end. The equaliser was offside. It's obvious because the linesman is on the line. He needs to see it," Klopp said.
"I cannot change it. We would have had defensive areas we need to work on even if we'd won 3-2, but we were the better team. We should have won."
As well as complaining about the officiating, Klopp was also frustrated by Liverpool's failure to finish off Watford.
Sadio Mane's 29th-minute effort had cancelled out Stefano Okaka's eighth-minute header, only for Abdoulaye Doucoure to immediately restore the home side's lead.
Liverpool were back level in the 55th minute through Roberto Firmino's penalty and new signing Mohamed Salah put them ahead in the 57th minute.
"The first half I wasn't too happy with. We passed but couldn't see what we actually wanted. The second half was a lot better," Klopp said.
"We forgot to close the game. We defended a little deep. We have to push up."