A late header from Lyle Taylor secured United a hard earned point at Port Vale on Tuesday evening.
Neal Bishop gave Mark Robins’ side a fifth minute advantage before Williamson drew Vale level and Chris Birchall then fired the hosts into a second half lead but Taylor ensured Scunthorpe came away with a share of the spoils.
Jennison Myrie-Williams was sent off for a second bookable offence and will miss Saturday’s game against Notts County as will Bishop, who picked up his fifth booking of the campaign.
The Iron made a trio of changes to the side that drew 1-1 against Colchester three days previously with Sean McAllister, the suspended Gary McSheffrey and the injured Rory Fallon all dropping out of the starting line-up and replaced by Isiah Osbourne, Terry Hawkridge and Lyle Taylor.
Scunthorpe got off to the perfect start in Staffordshire as Jennison Myrie-Williams found Luke O’Neill who then wriggled past his marker and whipped the ball towards Bishop at the near post and he poked home to net his third goal of the season.
Myrie-Williams almost doubled United’s advantage when he cut inside onto his left foot and unleashed a powerful drive from the edge of the area that was blocked by a Vale body when it looked destined for the bottom corner.
In what was a frantic start to the game, the hosts then scored an equaliser as Mark Marshall’s cross was nodded past Bobby Olejnik by Williamson to level things up with less than 10 minutes on the watch.
An accurate corner from Chris Lines landed right on the head of Carl Dickinson shortly after who diverted his effort narrowly wide of goal.
The menacing Myrie-Williams went close again at the other end as he received the ball from Hawkridge and proceeded to hit another left footed strike from distance that was well saved down low by home ‘keeper Chris Neal.
As the half-hour mark arrived, the contest calmed down slightly with both teams having difficulty coping with the blustery playing conditions.
But the away side had a golden chance to retake the lead with a few minutes of the opening period remaining as Hawkridge collected the ball in midfield and played Taylor through on goal. His attempt was pushed up in the air by Neal and heading for the back of the net but Richard Duffy was on hand to hack the ball away at the last.
No further opportunities arose before the break as referee James Adcock blew to signal the end of the first-half.
Robins’ men went close immediately after the interval as Myrie-Williams crossed to Paddy Madden who looped a header awkwardly under the crossbar but Neal clung on.
Vale almost scored themselves a matter of minutes later as Tom Pope darted into the Iron box and found Marshall but his nodded attempt was held by Olejnik.
United responded with another chance of their own as O’Neill’s deep centre was headed goal bound by Madden but the number nine saw his effort drift inches wide.
Billy Kee replaced Hawkridge as Scunthorpe went in search of another goal but opportunities proved few and far between as the midway stage of the second half passed.
The home side then took the lead for the first time on the night as Adam Yates’ powerful drive was palmed away by Olejnik but the ball fell straight to Birchall who volleyed Vale in front.
Myrie-Williams picked up his second yellow card of the game just minutes later for a late lunge on Lines and was given his marching orders but that didn’t stop the Iron from levelling things up once more.
O’Neill provided his second assist of the match as his free-kick was glanced into the far corner by Taylor and he very nearly turned the game on its head seconds after as he latched onto Bishop’s through ball and saw his resulting shot saved by the fingertips of Neal.
Sean McAllister and Deon Burton were both brought on as the game drew to a close but 2-2 was how things stayed and the two teams shared the points.
Port Vale: Neal, Yates, Dickinson, McGivern, Duffy, Dodds (Birchall, 65), Williamson (Slew, 85), Lines, Pope, O’Connor, Marshall.
Substitutes not used: Johnson, Brown, Moore, Veseli, Streete.
Scunthorpe United: Olejnik, O’Neill, Boyce, Brisley, Williams, Osbourne (McAlliser, 75), Bishop, Myrie-Williams, Hawkridge (Kee, 57), Madden, Taylor (Burton, 85).
Substitutes not used: Slocombe, Dawson, Llera, Adelakun.
Attendance: 3,590 (145 away).