Manchester United moved to joint top of the Premier League on New Year's Day.

Long gone are the memories of their first defeat to Arsenal at Old Trafford in 14 years as the Red Devils progressed to 10 league games unbeaten with a 2-1 win over Aston Villa.

Had we said that 12 months ago, it wouldn't necessarily have seemed like a huge result - though they did draw 2-2 in the same fixture last season - but it carries extra weight in the context of 2020/21.

Villa battle at Old Trafford

Besides, we're talking about an exciting Villa side that are launching an outside assault on the European places with an impressive record of eight wins, two draws and just five defeats.

And you could tell that Dean Smith's team meant business during the trip to the 'Theatre of Dreams' because they could actually feel aggrieved to have taken nothing from a thrilling encounter.

David de Gea was forced to make brilliant saves from John McGinn, Ollie Watkins and Matty Cash throughout the 90 minutes to ensure that Villa only rippled the net once on Friday.

Man Utd 2-1 Aston Villa

However, United did make the breakthrough before half-time when Anthony Martial headed home Aaron Wan-Bissaka's cross with the flight of the ball confusing Emiliano Martinez.

But Villa drew things level after the break with a quick free-kick and some typical wizardry from Jack Grealish carving out an opportunity for Bertrand Traore to score from close range.

Nevertheless, the incident on which the game hinged came a few minutes after Traore's finish when United won their latest in a long line of penalties since Bruno Fernandes arrived at the club.

Penalty and VAR controversy

The spot-kick was awarded after Paul Pogba looked to have been brought down by Douglas Luiz, but replays suggested that the incident was incredibly soft despite VAR checking it over.

And with both the referee and technology in agreement, much to Villa's bewilderment, Fernandes stepped up to make it 2-1 by firing the ball past Martinez and into the bottom corner.

However, the decision clearly left a sour taste in the mouth of the Villa players because a few of them have taken to Twitter in the hours since - and few more passionately than Luiz himself.

Douglas Luiz takes to Twitter

The Brazilian has attracted more than 5,000 retweets and 18,000 'likes' for calling out VAR on Twitter with a pair of videos, which, in his opinion, show United were wrong to earn a penalty.

The tweet roughly translates as: "I see this video, I can't believe it was a penalty, I always support fairer football, with fewer mistakes, but then I stop and see these types of moves.

"If we have VAR to help, LET'S start using it CORRECTLY, these mistakes can define the future of clubs!"

He then followed that up by posting another video with a caption along the lines of: "This is just to show more clearly !! @AVFCOfficial @premierleague" 

Luiz even retweeted a fan response, which included a viral video that many think shows Pogba encouraging Luke Shaw to dive, to vent his frustration even more. 

Martinez backs up Luiz

The 22-year-old wasn't alone in taking to Twitter after the incident either with Martinez replying to a video of Pogba going to ground by posting 'Highlight of the game' and an angry face emoji. 

In fairness to Villa, you really have to wonder whether the incident was clear enough for United to earn the penalty, particularly upon review from VAR, because the contact looked to be minimal.

But for all their justified frustration, one can't help thinking that Luiz and Martinez's grievances with VAR with fall on deaf ears until all players, if they so choose, stand up against the technology.