Harris has reached the landmark in his second spell with the Tigers having previously managed them from 2006-08.
Goals from Joseph Parker, Karnell Chambers and Christopher Knowles made it a day to remember for their boss despite Enoch Andoh getting one back for the visitors.
Harris told the club's website: "I've enjoyed every minute of it, it's a fantastic club.
"The only downside, what everybody says, is that we've got to get back home because it is killing us.
"I don't know what the support was today but the hardcore of fans are fantastic, they enjoy the away trips more than the home trips.
"Being back in the city is a must and we've got to pull out the stops to do that as soon as possible."
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