Jon Parkin came off the bench to give in-form Scunthorpe victory over relegation-threatened Exeter.
The visitors' Lauri Dalla Valle spurned a great chance when he headed straight at keeper Sam Slocombe from close in.
The woodwork then denied the Iron twice in quick succession when Josh Walker's strike came back off the bar before Jimmy Ryan's effort struck the post.
Scunthorpe, though, finally got the breakthrough when Jamie Reckford cut back to Parkin who fired home.
The hosts could have had more had it not been for Grecians keeper Artrur Krysiak, who twice pulled off fine saves to keep out on-loan striker Conor McAleny.
Defeat leaves Exeter eight points adrift of safety whilst Scunthorpe, who remain unbeaten in nine league games, move seven points clear of the relegation zone.
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Scunthorpe United boss Alan Knill told BBC Radio Humberside:
"I'm delighted with the result - it was a tough game, and with the greatest of respect we played Chesterfield last week, Exeter this week; they really have nothing to lose, they have to go for it to get the points, so they're always dangerous on the counter attack.
"I thought the second half that we were dangerous; a lot more than the first half, and could have had more goals, but we just needed the one to take the points.
"We just decided to throw Jon (Parkin) on, and he just brings a presence and thankfully brought a goal."
Exeter City manager Paul Tisdale told BBC Radio Devon:
"I think we played with a lot of cohesion and purpose.
"I'm bitterly disappointed because the performance was very good, we just failed to score and conceded a goal at the wrong time.
"It's hard to fault that first hour in terms of how we approached the game, against a very hard working and creative opposition.
"It's not over until it's over, we can only try to win the next game."