Havant conceded within 30 seconds of their match against Milton Keynes before going on to win 5-2 in South League premier division one.
However, the visitors recovered from the early set-back and took control of the game thanks to goals from Mike Deller-Merricks and Oliver Nail.
Sandeep Singh also returned to form with a hat-trick from penalty corners.
Jamie Dodd and Ali McColl replied for the hosts.
It was a welcome victory after last week’s miserable defeat to Sevenoaks, which ended all hope of promotion to the National League.
Havant only took 13 players to Milton Keynes due to injuries and unavailability.
Jamie Whitehouse and JJ Brown were both missing through injury.
They also missed the energy of midfielder Laurie Bowden, who was on an England training camp.
‘We were slow to get started,’ admitted Havant coach Ady Adams.
‘It was a long ball up the middle of the pitch and they scored from an acute angle and caught everyone off guard.
‘But that didn’t put us off and we got back into it.
‘I think we were fairly comfortable after that.
‘Once we conceded, I always thought we could score goals.
‘The big game players came to the fore.’
The Barncroft Way side have now cemented third place in the table with three matches of the campaign remaining.
Adams added: ‘The result was more important than the performance on the back of last week’s defeat to Sevenoaks.
‘The pitch was very slow and very sticky which didn’t contribute to a free-flowing game.
‘Credit to Milton Keynes, they’re in a dog fight at the bottom of the table and they came out and tried to play hockey.’
Elsewhere, Tom Murtagh scored seven goals for Havant II as they thumped Southampton 11-1 in their Hampshire/Surrey division one encounter at Havant College.
Also on target were Davis Taylor-Bargent, South African Saatchi Reddy, George Hughes-Stanton and Tomek Bruml.