The Gunners had taken an early lead through Nikolaj Moller just after the five-minute mark, but Hein was given his marching orders soon after for bringing down Felix Nmecha just outside the box.
Our opponents shut up shop and offered a stern test for the Young Blues, but goals from Nmecha and James McAtee plus late strikes from Liam Delap and Alpha Dionkou sealed a hard-fought win.
But while Maresca was pleased with the result, he also highlighted some of the challenges that playing against ten men can present.
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He said: “Sometimes it looks easier (to play against ten men) but it’s not like this… I think we could be a little bit more quick with the ball, we slowed down a little too much.
“But I also understand against ten players when they are all close (together) it’s not easy to find space.
“The most important thing was the three points, three wins in a row and in the table we are better now.”
With the scores level at 1-1 going into the break, Maresca switched to a back three to help us make more of our man advantage in the middle, bringing McAtee into the fold as support for Delap.
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And it proved to be an inspired decision, with the substitute on the scoresheet within fifteen minutes of the restart, before Delap too got in on the act with just over five minutes to go.
Maresca explained his thinking behind the tactical shift: “When (Arsenal) were with ten, you need to modify something to find a different solution.
“And the solution was three at the back with McAtee in behind Liam (Delap) to try to find something.
“It’s always difficult to score goals… we scored four today, we missed many chances but that also means we created them too.”
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