It gives them a commanding five point lead on Stockport County and Carlisle United with three games to go.
Victory over Harrogate Town at the weekend could be enough to seal promotion back to League One if other results go there way.
It will be a much-deserved promotion for a Cobblers side who have been up there all season.
Is it a promotion they will get? Here is the supercomputer’s prediction.
Get more Cobblers news, here.
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Northampton Town took a big step towards promotion with victory at Sutton United last night. Photo: Pete Norton
. Leyton Orient - 90pts (+27)
Win the league: 97% Photo: Pete Norton
. Stevenage - 82pts (+19)
Promotion: 77%
Play-offs: 27% Photo: Pete Norton
. Northampton Town - 82pts (+19)
Promotion: 83%
Play-offs: 21% Photo: Pete Norton
. Stockport County - 78pts (+27)
Promotion: 43%
Play-offs: 80% Photo: Naomi Baker
. Bradford City - 77pts (+19)
Promotion: 35%
Play-offs: 75% Photo: Pete Norton
. Carlisle United - 76pts (+23)
Promotion: 25%
Play-offs: 81% Photo: Pete Norton
. Mansfield Town - 75pts (+17)
Promotion: 23%
Play-offs: 68% Photo: Chris Holloway
. Salford City - 74pts (+18)
Promotion: 14%
Play-off: 50% Photo: Alex Pantling
1. Leyton Orient - 90pts (+27)
Win the league: 97% Photo: Pete Norton
2. Stevenage - 82pts (+19)
Promotion: 77%
Play-offs: 27% Photo: Pete Norton
3. Northampton Town - 82pts (+19)
Promotion: 83%
Play-offs: 21% Photo: Pete Norton
4. Stockport County - 78pts (+27)
Promotion: 43%
Play-offs: 80% Photo: Naomi Baker