The match - Bayern's first of two pre-season friendlies as part of their summer US tour - was only five minutes old when Mane opened his account. Teenaged forward Lucas Copado went to ground in the penalty box under Donovan Pines's challenge, and the new Bayern No.17 dispatched his spot-kick with aplomb. Serge Gnabry and Leroy Sane combined to set up Marcel Sabitzer for an arrowed finish from 18 yards, before record champions Bayern added a third. African Player of the Year 2022 candidate Mane, having provided the cross for Gnabry's deflected strike, then had two goals ruled out for offside in a one-sided end to the first half.
Julian Nagelsmann rotated his entire starting line-up at the break, with Thomas Müller and new signing de Ligt among the introductions. The duo combined for Bayern's fourth, with de Ligt thumping in from close range after Müller had flicked on a Joshua Kimmich corner. Müller was the catalyst for the next goal with a cross that Kingsley Coman calmly cut back for Joshua Zirkzee to sweep in. Skage Simonsen pulled one back when de Ligt's attempted clearance came back off the upright, before Sven Ulreich thwarted Pines and Bayern debutant Ryan Gravenberch ballooned over. DC's Ted Ku-Dipietro further reduced the arrears, but Müller had the final say with a smart finish to Gravenberch's eye-of-the-needle assist.
Six different players scored for Bayern.
Mane managed 45 minutes on his Bayern debut, while de Ligt enjoyed a 20-minute cameo.
It gets better for Bayern. Kimmich swings over a corner that's flicked on by one half-time substitute to another. Müller wins it, with de Ligt hammering high into the net from close range. Nagelsmann said the Dutch defender would get goals...
Bayern have a comfortable lead in the US capital. Mane's had a hand in two of their three goals, whilst having two more ruled out. Dream start to his Bayern career, and still 45 minutes to play at Audi Field.
ANOTHER DISALLOWED MANE GOAL
This one's a lot closer as Mane clips in what he thinks is his second of the contest, before the linesman's flag goes up for offside.
DISALLOWED MANE GOAL
Mane fires home from inside the area, but the DC defence had long stepped up. He was clearly offside.
Clinical from Bayern. Sane wins the ball back in the DC half, and helps it on to Davies. He feeds Mane, who sends in a cross from the left. Gnabry controls and fires goalwards, with a deflection wrongfooting the keeper as the ball nestles into the back of the DC net.
Sabitzer curls a delightful ball towards the far post for Copado, but his first touch lets him down and the keeper is out to gather.
DC threaten for the first time as a free-kick is sent into the box from the left. Davies blocks the first effort and Upamecano the second, before a shot from range is sent wide of Neuer's left-hand post.
The players have the chance to take some fluids on board. The mercury is around 35C in the US capital...
PASS AND MOVE
Davies uses his muscular frame to break up a DC attack. Bayern turn defence into attack, with a deflected through-ball almost putting a second goal on a plate for Mane. The home keeper is first to it, though.
DC United attack for the first time with Najar, but Davies - aka the Bayern Roadrunner - recovers the ground and steps in to prevent the cross. The ensuing corner comes to nothing.
Bayern turn the screw and double the lead. It's a superb goal - fantastic interchange between Gnabry and Sane as the ball is worked in off the left to Sabitzer. He's in a central postion on the edge of the area and whips home with aplomb.
Julian Nagelsmann's team are pressing DC hard in the early stages. Davies and Sane are looking a realy threat down the Bayern left...
The two teams pose for a joint photograph ahead of kick-off. It's quite the atmosphere - plenty of support for the record champions.
AFRICAN PLAYER OF THE YEAR
Mane will head to Morocco after the game for the African Player of the Year ceremony. The Senegal forward is a favourite to claim the prize he won in 2019, following a sensational season for club and country. The award ceremony is on Thursday evening (local time).
WATCH: THE LEWANDOWSKI STORY
It's a new era at Bayern, following eight goal-filled Lewandowski years. He leaves the club for Barcelona on 312 goals from 384 appearances, and as a true Bundesliga legend.
DAVIES HAILS MANE & DE LIGT SIGNINGS
"Having those two players on the team really motivates us, because they're big talents coming in," Alphonso Davies said of Mane and de Ligt. "Obviously Mane has won the Champions League as well, and De Ligt is a young player hungry to win more trophies. We're just happy to have them on the team."
New Bayern defender Matthijs de Ligt could make his debut from the bench at Audi Field. The Netherlands international has taken the No.4 shit previously worn by Niklas Süle. "Bayern are one of the biggest clubs in the world," said the 22-year-old at his unveiling.
WATCH: MANE'S FIRST TRAINING SESSION WITH BAYERN
"When they talked to me, especially the coach, they told me the team, how they play, and tactical stuff as well. I was so fascinated," Mane said of his decision to join Bayern. "Straightaway I could see myself in it. Then I didn’t even think twice – it’s the team for me. I think of course I can help the team to achieve things together."
WATCH: RELIVE SADIO MANE'S UNVEILING
Mane joined Bayern in June, on a three-year deal. The 30-year-old produced 120 goals and 48 assists in 269 competitive appearances for former club Liverpool.
The Senegal forward goes straight into the starting line-up at Audi Field, with Noussair Mazraoui also handed his debut. Teenagers Gabriel Vidovic and Lucas Copada are surprise inclusions. Matthijs de Ligt and Ryan Gravenberch begin the game on the bench, alongside the likes of Joshua Kimmich and Thomas Müller.
Bayern Munich are in action for the first time since Sadio Mane joined the club from Liverpool. DC United are the opposition, in the record champions' first pre-season friendly of their 2022 US Tour. Stay tuned!