On Tuesday Diallo spoke of his desire to remain with United "for life".

He also said he met fellow Ivorian Yaya Toure on holiday in the Maldives, where the former Barcelona and Manchester City star offered some advice for the season that lies ahead.

There was certainly a purpose about Diallo at the Snapdragon Stadium.

The 22-year-old was clean though twice but on the first occasion opted to nudge the ball on to Jadon Sancho, who was offside, while Scott McTominay burst on to the loose ball on the second occasion, only to go down under the tackle that followed and not be rewarded with a free-kick.

It was Diallo's purposeful burst almost immediately after Iker Losada had prodded Betis in front that did bring the penalty that allowed Rashford to level.

Diallo is clearly full of confidence and his goal showed it as Harry Amass’ left-wing cross bounced perfectly for the powerful drive into the bottom corner that followed.

Diallo had a couple of forceful runs in the second half before he was replaced, with a few others, after an hour.

Manager Erik ten Hag challenged Diallo at the start of this trip, declaring "this has to be his year".

Diallo seems to agree.

“He was dynamite,” said United goalkeeper Tom Heaton about Diallo.

“Since I have been here his ability has been incredible. Now you see more confidence and more belief and he is getting more game time, then you can see his game coming together.”

Under the circumstances, Ten Hag could do without suffering any more injuries before the season starts and United did not seem impressed at what they perceived was a soft refereeing performance from Alexis da Silva, an MLS regular.

Rashford was on the wrong end of a couple of tough challenges. He needed treatment after the second, when Da Silva appeared not to notice the England forward getting caught on the ankle inside the box, and eventually went off.

Rashford was not moving freely but it was not clear whether the substitution was pre-planned as, within a couple of minutes, United made half a dozen.

Antony only lasted 23 minutes of the second half before he was forced off. The Brazilian indicated to reporters afterwards he had hurt his hand.

It was a special night for Heaton.

The 38-year-old has not played a competitive game since February 2023 and told BBC Sport last week of his hope he would get more opportunities this season.

Although he admitted responsibility for Real Betis’ opening goal, he still enjoyed playing in front of a crowd of over 20,000.

“Yes is the honest answer,” he said, when asked if it felt good to play. “It was fantastic to be out there. The feeling you get when you play is incredible. I love it.

“Other than bounce (practice) games it has been a while since I had a proper 90 minutes. It felt quick at times but I built into the game.”