Casemiro was sent off as Manchester United fell to defeat at the hands of Galatasaray in the Champions League on Tuesday night.

The home side took the lead twice in the match but were stunned in the second half as the visitors claimed a 3-2 win.

We pick out five key talking points from an entertaining contest at Old Trafford.

United front

United's clash with Galatasaray was Erik ten Hag's first Champions League match at Old Trafford and the crowd were deafening as they urged their team on in the opening exchanges.

A fast start led by captain Bruno Fernandes created enough noise to drown out the raucous travelling supporters from Turkey initially but the Galatasaray fans soon found their voice after withstanding a few dangerous attacks from the hosts.

The Premier League defeat to Crystal Palace at the weekend did not seem to deter the Red Devils, who pressed high and looked to dominate possession.

And although a great opportunity by Hannibal Mejbri was wasted at the 10-minute mark, it only increased the volume inside the Theatre of Dreams.

Hojlund heroics

The fans continued to dictate the pace of the game and the crowd's work from the stands soon paved the way for the first goal of the night.

Rasmus Hojlund was denied his first league goal for United against Brighton a few weeks ago but his persistence has paid off under the lights in Europe.

Marcus Rashford was the man to deliver an inch-perfect cross into the Dane's path and the 20-year-old made no mistake from six yards out to bag his second goal in as many games in Europe's top competition.

His presence in the final third remained superb throughout the game and the heavy downpour of rain would not stop Hojlund from grabbing his brace at the Stretford End.

Welcome back Wilf

Ex-United speedster Wilfried Zaha played it cool in front of the cameras ahead of the reunion with his former club and the Ivorian unsurprisingly looked dangerous on his old stomping ground.

His battle with Diogo Dalot looked to be a mismatch, with the talented winger playing off the shoulder of United's No20 where he was able to beat him for pace almost every time they faced up.

The 30-year-old also got on the scoresheet for his first goal in the Champions League and it was Dalot who he held off before bouncing an effort over Onana and into the net.

Zaha continued to threaten in the game but received the same rough-and-tumble treatment he got for many years in the Premier League before eventually being replaced by former Napoli striker Dries Mertens.

Unwanted impact

Mejbri was withdrawn at half-time and replaced by Christian Eriksen, who looked to have changed the game for the Red Devils.

The midfield maestro was constantly able to pick the ball up in the middle of the pitch and spray passes into the final third, allowing United to pile on a barrage of attacks in the second half.

Both Rashford and Fernandes were stretching the pitch well but it was the same old story for the hosts as they failed to protect their lead again despite Hojlund's heroics.

Ten Hag's attacking gamble proved to be a risky one and gaps opened up in United's defence — ultimately letting Galatasaray back into the game and eventually allowing them to record their first away win in the Champions League since 2013.

Turkish delight

With the game finely poised at 2-2, United were dealt a huge blow when Casemiro gave away a penalty — and received a second yellow card — for a reckless tackle.

It looked to be despair for the Super Lig side when Mauro Icardi stepped up and sent his effort wide but the seasoned striker made up for his mistake minutes later.

The lack of a defensive midfielder allowed the 30-year-old to drive in on goal and chip over the onrushing Andre Onana to send the visiting supporters into raptures late on.

A chorus of boos rang around the Theatre of Dreams at full-time as United recorded their second defeat in three days.