United took the lead in the 29th minute when Marcus Rashford fired into the top corner from inside the box.
That was a really, really poor performance
And the teenager made it 2-0 moments later when he blasted home from close range.
Arsenal pulled a goal back when Danny Welbeck headed Mesut Ozil’s free-kick into the near post before half-time.
However, Ander Herrera’s deflected shot restored Manchester United’s two-goal lead in the 65th minute.
Ozil pulled a goal back for the Gunners in the 69th minute but the north London side were unable to conjure an equaliser at Old Trafford.
Speaking on Sky Sports after the final whistle, Henry said: “That wasn’t a performance of a team that wants to be champions.
“As an Arsenal fan, I’m looking at it, I’m not sure they can be champions.
“Today, they didn’t reassure me on anything. The only thing that’s good is that they’re still in the title race.
“Other than that, today they were second-best in everything. That was a really, really poor performance.
“But don’t take anything away from Marcus Rashford and Manchester United today.
“But, come on, Arsenal had to do a bit more than that today and they didn’t.”
The result left Arsenal third in the table and three points behind second-placed Tottenham, and five behind leaders Leicester heading into the final 12 games of the season.
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