The referee had a huge influence on the game as eight bookings and a dismissal punctuated the game.
Scunthorpe should have taken a third-minute lead when the Swans' Mark Wilson pulled down Matt Sparrow, but Kevin Sharp hosted the resulting spot-kick over the bar.
Swansea were buoyed by the miss and took a seventh minute lead when Lee Trundle curled in a fine left foot shot passed Tommy Evans.
Two minutes later Scunthorpe were back in the game, Steve McLean found Alex Calvo-Garcia on the goal line and it was easy for him to tap the ball home.
The Iron went ahead when they were awarded a second penalty in the 58th minute when Izzy Iriekpen pulled down McLean. The defender received a straight red card and McLean fired home from the spot.
The indefatigable Welsh men struck back six minutes later, predictably it was Trundle with his eighth goal in seven games who earned them a point.
Matty Sparrow was unlucky when he saw Roger Freestone stop a shot with his legs while substitute Paul Hayes flicked the ball over the keeper only to see Maylett clear off the Swans' line.