Joining from Eastleigh, where he had helped lay the foundations of their play-off push, he knew he was putting his reputation on the line.
But now that risk looks like it was worth taking.
On Saturday, Hessenthaler celebrated as he kept Dover in the division with three games to go.
Just staying up when he join, the club 23rd in the league and winning just one of their 15 National League games, seemed a very tall order.
He probably knew they weren’t going to do it the easy way at Barrow, 2-0 down and staring at a long trip home with plenty on their minds.
But they boarded the coach not only safe but ecstatic as the Whites came back from the dead to score three times in the final 17 minutes.
Hessenthaler said: “It’s been a long road but I’m over the moon that we’ve been able to do it.
“We’ve achieved the objective and we have done it with a few weeks to go.
“The club weren’t in a good position but we have worked hard and the players deserve so much credit.
“I thought we were dead and buried and Barrow but we changed the shape and it worked. I’m delighted for everyone.”