Both Manchester clubs continued their impressive starts to the Premier League season to remain at the summit.While Manchester City eased to three points with a 5-0 victory over Crystal Palace, Manchester United had to work a bit harder for their three points.Jose Mourinho’s side struggled past Southampton at St.Mary’s, winning 1-0 thanks to Romelu Lukaku’s sixth goal of the campaign.But during the end of the match, they were holding on.And when Southampton got a penalty in the 94th minute, it was ‘squeaky bum time.’But Mourinho wasn’t anywhere to be seen.Instead, the Portuguese boss had made his way to the dressing room after receiving his marching orders.Quite why Mourinho got sent off in unknown - although some believe it was because he left his technical area. And the below picture may explain it:

But the ‘Special One’ was certainly in the dark about his dismissal.

“I don't know. You should ask the referee,” he said after the game.

Mourinho certainly didn’t appear to be too annoyed by his sending-off.

That’s because after Craig Pawson dismissed him, Mourinho decided he would take the time to shake the hand of every member of Southampton’s staff, before giving a little wave to the players on the bench.

Watch: Mourinho's reaction to getting sent off

Take a look:

Of course, it was just a couple of weeks ago that Mourinho was heavily criticised for refusing to shake Mark Hughes’ hand after they drew 2-2 with Stoke.

Twitter reacts

And this is how everyone on Twitter reacted to Mourinho’s behaviour:

Despite a fairly unconvincing victory, Mourinho was “really happy” with earning maximum points.

“It’s the same number of points as when we win 4-0," he said.

"Difficult place to come against a good opp with nothing lto lose. In the last 25 mins they were very offensive and tried to take the point.

"We had chances to kill the game and we didn’t tackle them and we put ourselves into a position to defend to preserve the result which we did extremely well. I am really happy.”