Manchester United manager David Moyes has fumed at referee Mark Clattenburg after Liverpool were awarded three penalties and captain Nemanja Vidic was sent off in the defeat to The Reds at Old Trafford.
Steven Gerrard scored two penalties and Luis Suarez struck late as Liverpool enhanced their Premier League title challenge by going second to within four points of leaders Chelsea.
Though Brendan Rodgers' side controlled the game for long periods, referee Clattenburg was forced into awarding three spot kicks, the third of which led to the dismissal of Vidic for a second booking for a challenge on Daniel Sturridge.
Replays later suggest Sturridge had dived to win the third penalty which saw Gerrard hit the post and though Rafael was fortunate not to be dismissed after committing a deliberate handball and a series of cynical fouls, Moyes was unhappy with the general level of officiating.
"It is better we don't talk about any of them [the penalties]," the United boss said. "Some were penalties, some weren't."
United's 9th defeat of the season all but ends their pursuit of both reclaiming their league title and finishing in the fourth Champions League place.
Olympiakos travel to Old Trafford on Wednesday in the Champions League last 16 second leg with United tasked with overcoming a two-goal deficit from the first leg and Moyes has called on the club's fans to inspire a turnaround in fortunes.
"I thought there was not a great deal in it at half time," he added. "We had just started to play a bit better towards the end of the first half.
"It was important we came out in the second half and got a goal back but instead we gave one away and that made it very difficult for us.
"I don't think I had even got seated in the dugout when we gave it away. We were going for it but it always left us open to a counter."
"The support was phenomenal today and if they give us that again we will have a great chance on Wednesday.
"It looks like we are long way off it [the top four], we are well aware of that but we are going to keep fighting."