Jim Goodwin named a United side without their recognised spine - no Ross Graham, Ross Docherty, Craig Sibbald or Louis Moult - and they started on the back-foot, happy to absorb any Hibs pressure.
However, they took the lead when Glenn Middleton burst away from Lewis Miller and squared for Dalby, who did well to poke home ahead of O’Hora.
Hibs were threatening from set pieces, though, and eventually levelled through O’Hora, who nodded in a headed cut-back from Miller.
It was a fair scoreline at the break, before a second 45 minutes that was far more entertaining.
United thought they were ahead almost immediately after the restart when Middleton crossed for Dalby, who powered past the defenders to score. However, it was deemed offside after a VAR check and Hibs’ were jolted into action.
Jordan Obita’s brilliant ball in was powered in at the back-post by substitute Dwight Gayle, and it looked like Hibs were set for only a second win of the league season.
They made that task harder when Newell walked for his second yellow on 85 minutes - a tackle on Stephenson that was also checked as a possible straight red.
After that, a United goal seemed inevitable, and it came when Bursik flapped at a Kristijan Trapanovski cross, with the ball dropping for Stephenson to tuck home.
Perhaps the winner should have been no surprise.
Another calamity at the back - Bursik punching defender Jack Iredale instead of the ball - allowed Meshack the chance to lob into an empty net and he did just that.