David Syers put Scunthorpe ahead in the 79th minute, converting an Eddie Nolan cross from the right that had been helped on by sub Paul Hayes.
Plymouth responded with Lewis Alessandra hit the post for a second time in the second half but Scunthorpe put the game beyond doubt when Hakeeb Adelakun's 20-yard drive hit the upright and went in off the unfortunate Jake Cole.
Wilcox said: "We are hoping this kicks us on because we need to refocus for Burton now.
"That's 21 unbeaten, you can throw draws in there but it doesn't matter. My players should be really proud because that it is a record that will take some beating.
"I hope the record goes even further because that will mean we will be staying in that top three.
"We have not over-analysed the wins and we are certainly not going to analyse the draws. If a defeat is around the corner, we will be the same.
"It is just about putting the next one to bed and it is fantastic to put this one to bed with an outstanding performance and result. We have married both of these together which is really pleasing. It is a long way home but it will make a lot sweeter.
"Today the lads showed we haven't lost any confidence, we were very brave and deserved the three points. We got it spot on and we don't do that every week. We retained and moved the ball really well. The key word today was the bravery of the players with the ball."
- Sports & Recreation
- Lewis Alessandra
- Paul Hayes
- Hakeeb Adelakun
- David Syers