Veteran winger Peter Beagrie made all the early running for United, testing the visiting goalkeeper with two early efforts - including a free-kick which clipped the top of the bar.
Alsop and Hunt both had opportunities for the visitors, who took the lead four minutes before the break when Nathan Stanton pulled Steve Basham back on the goaline to concede a penalty.
Andy Crosby struck the ball to the right past Evans to open the scoring.
United fought back after the break, with Steve Torpey heading over moments after the restart.
The equaliser came in the 63rd minute, when Beagrie forced his way into the box and firing the ball into the far corner.
Scunthorpe pushed for a winning goal, but the best they could muster was a Torpey header which went well wide.