Northampton eased away from the relegation zone as goals by Tyler Roberts and Cameron McGeehan fashioned a deserved 2-1 away win at Leyton Orient.
The Cobblers opened their account on 11 minutes when Roberts headed in a corner from close range following a corner by Terry Taylor.
The lead was doubled on 45 minutes when Os defender Jack Simpson failed to control a pass and McGeehan had the simplest of opportunities to steer the ball past keeper Josh Keeley for his ninth goal of the season.
Orient were twice denied by the woodwork as Regan Williams saw his 24th-minute effort strike the crossbar and then Dan Agyei worked an opening for himself on 39 minutes only to hit the far upright.
In the 60th minute, leading scorer Charlie Kelman notched his 16th goal of the campaign when Agyei nodded on for the striker to finish.
But the home side were unable to add another chance as they slipped to their fifth consecutive defeat to diminish their hopes of making the play-offs.
Subscribe or register today to discover more from DonegalLive.ie
Buy the e-paper of the Donegal Democrat, Donegal People's Press, Donegal Post and Inish Times here for instant access to Donegal's premier news titles.
Keep up with the latest news from Donegal with our daily newsletter featuring the most important stories of the day delivered to your inbox every evening at 5pm.