Arsenal had to come from behind to secure a 2-1 win over rivals Manchester United at the SoFi Stadium in California, on Saturday.

Goals from the Brazilian duo of Gabriel Jesus and Gabriel Martinelli cancelled out Rasmus Hojlund's early opener - before he limped off injured.

Despite the Gunners claiming the victory, there was a penalty shootout held after the match which United reigned supreme in, winning 4-3 over the North London side.

It proved an important night for many of Arsenal's stars as they get the minutes in before their battle with Manchester City resumes when the Premier League season begins against Wolves on 17 August.

Mail Sport's Isaan Khan was in Los Angeles to witness Mikel Arteta's side topple United. Here are five things we learned from the night.

Gabriel Martinelli (right) came off the bench to complete a comeback win for Arsenal 

Jesus impresses up top

As Gabriel Jesus drifted past a Manchester United defender with a backheel flick, echoes of Arsenal’s away fixture to Sevilla in October sprung to mind.

He had evaded two players on that occasion with sublime trickery to provide Gabriel Martinelli with a goal.

In the following months, hamstring and knee injuries plagued him and his performances and game time were affected.

Here there were glimpses of Jesus at his capable best, stretching the United backline, penetrating between the pockets to cause real problems.

The striker has that ability to not only score goals — he got one tonight — but also maraud forward with the ball.

Arsenal scored 91 goals last season with a plethora of scorers across the squad, yet still, there have been calls for a forward after falling short to Manchester City.

If Jesus can stay fit across the duration of a season, the Gunners will have plenty of firepower up top.

17-year-old Nwaneri takes his chance

He only played the first half, but Ethan Nwaneri sure made the most of his cameo.

It was his assist for Jesus’ opening goal, whipping in a low cross evading the backline, that showed a sign of his talents — and why he should be around the first team squad this season.

He had a shot at goal after 10 minutes ruled offside, and an impressive cross-field pass later in the half.

Though it was his overall composure and eagerness on the ball which shone. This level does not appear to faze Nwaneri and after failing to break through in the previous campaign, the next step surely beckons.

Similarly, fellow academy player Ayden Heaven showed promise. He was outmuscled and brushed aside by Rasmus Hojlund for Man United’s first goal but recovered well afterwards. His composure on the ball stood out for a defender. It’s bearing in mind that he is a midfielder who has been converted to a new position only recently. So there’s much room for development.

Good signs ahead of a big season for the Gunners.

Big guns return 

The Arsenal big guns — Gabriel, Gabriel Martinelli and Kai Havertz — arrived in the US yesterday after a prolonged rest owing to their involvement in the Euros.

The latter two were substituted on 71 minutes, after Gabriel, for a runout. It was Martinelli who wasted no time in reminding Mikel Arteta of his qualities after losing his place to Leandro Trossard in the latter part of last season.

He provided a threatening cross to no avail on 73 minutes, before scoring a goal of sheer class.

On the left wing, Martinelli cut in with a burst of power to leave the ball a yard ahead of him. He ran ahead of those in his wake to latch on and strike past Andre Onana.

The Brazilian looked fresh ahead of the new campaign, and intimidating whenever he received the ball.

It’s that ability to either cut inwards or reach the touchline for a cross which proves problematic to face.

As seen in recent months, Arteta is not afraid of making changes. A good pre-season camp will throw Martinelli right back into the fore once again.

No pitch problems this year 

After last year’s pitch debacle, the SoFi Stadium executives were desperate to ensure a repeat would not occur. It didn’t. The pitch was in good nick, a splash of water sprinkled prior to kick-off.

A contrast to Arsenal’s match against Barcelona one year ago in which ground staff were scurrying to patch up pitch problems. The game, as a result, was delayed by 30 minutes, and Mikel Arteta raised concerns about the pitch’s safety.

It was good to see those worries addressed, and fitting owing to the impressive nature of the stadium. Other changes which are to be implemented include extra width on the touchline because the space near the corner flags don’t match FIFA’s new pitch size regulations.

A double-sided oval video board takes centre stage in an arena that oozes extravagance. It’s the first indoor-outdoor stadium to be built and 3.1 million square feet.

A not-fit-for-purpose playing pitch would have detracted from that.

US put on unique show 

Los Angeles provided a flavour of US pageantry to the travelling English contingent. Arsenal’s North London Forever anthem, which is blared out at every match at the Emirates, was played ahead of kick-off. A sense of home away from home.

But there was also the twist of having the US anthem played once the players lined up on the pitch. Everyone stood, including the media.

Another quirk was the game kicking off 10 minutes past the 5pm kick-off time. It took until five past before the players had even come out.

The US market for soccer is growing and growing so more such events are to be expected.

A promising sign is how seriously the States takes these friendlies and pull out the stops to maximise fan experience. It’s certainly unique.