The Cottagers stunned the Reds at Craven Cottage in their Premier League opener, and while Liverpool came back to draw 2-2, there was controversy surrounding the hosts' second goal.
Prolific in the Championship, there have been major doubts over Mitrovic on this return to Premier League football having previously struggled to perform in the top flight.
He answered those doubts in perfect style with two goals as Fulham stunned Jurgen Klopp's side with a high-energy display, but there will be questions asked over his second strike from the spot.
Collecting the ball outside the box, Mitrovic dribbled into the area looking to take on Van Dijk, and left the referee immediately pointing to the spot as he went to ground.
Initially, it appeared Van Dijk had kicked the ball away from the defender, with the defender waving his arms to tell the striker to get back up.
Replays told a different story, though, as the Dutchman didn't actually touch the ball.
Whether or not there was conduct was also up for debate and talkSPORT pundit Andy Townsend was in no doubt - Mitrovic dived.
"I saw Van Dijk say to the referee, 'no chance' and it looked like Mitrovic went down a little easily, for me," Townsend said from the commentary box at Craven Cottage.
"Does he offer out a leg towards Van Dijk? I'm not sure he touches him, but either way it's not good defending.
"I didn't see a lot of contact and if there's no contract you can't give it.
"It looks like a dive to me. He hasn't touched him.
"The referee has got to have a look at the monitor there. If there is serious doubt over whether that was a penalty, he simply has to look at the monitor.
"It's a contentious pen, I didn't see a lot of contact.
"I'd love to hear the talk between the refs. We should be capable of that. Nobody in this ground had a clue what was happening, so we should be doing it."
Townsend was full of praise for Mitrovic's performance, though and said he deserved his two goals, no matter how contentious the penalty was.
"However, I think Mitrovic has played really well today," he added.
"He's not going to win a footrace with the likes of Van Dijk, but he's played his own game perfectly.
"He's led the line well, held it up, his first headed goal was fantastic, and he ghosted into the area with the ball at his feet for that penalty.
"It'll be interesting to see what he can do for Fulham this season. He's been outstanding, he really has."
However, not everyone agreed with Townsend, as former Aston Villa striker Gabby Agbonlahor tweeted he thought it was definitely a penalty, adding he thought the Reds were still on holiday.