The Gunners headed into their clash against the Tigers desperately looking to return to winning ways after the disappointment of their back to back defeats by Watford and Chelsea left their Premier League title hopes in tatters.
Sanchez scored Arsenal’s opener in the 34th minute at The Emirates when he bundled the ball over the line after it bounced off his hand.
The Chilean then added a second in second-half stoppage time from the penalty spot to wrap up the three points.
The controversial opener was allowed to stand by referee Mark Clattenburg, and Henry conceded that the Gunners were fortunate the goal counted.
Speaking during Sky Sports‘ coverage of the game, Henry said: “Is it deliberate? No. It’s a goal but I could have understood if it was disallowed.
“How can you see it also? It’s one where if you’re on that side [Hull], you’re complaining.”
The win left Arsenal in third place in the Premier League table and nine points behind leaders Chelsea, who travel to Burnley in the top flight on Sunday.
The Gunners take on Bayern Munich in the first leg of their Champions League last-16 tie on Wednesday night in Germany.
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