Sutton put their Papa John’s Trophy final heartache behind them to beat Leyton Orient 1-0 and stay in the hunt for a League Two play-off place.
The U’s lost to League One Rotherham in extra-time at Wembley last weekend.
But Joe Kizzi bagged his sixth goal of the season to leave United two points off the top seven with a game in hand over the majority of their play-off rivals.
Rob Milsom’s cross-turned-shot almost caught Lawrence Vigouroux out early on.
Harry Beautyman’s strike forced a fine acrobatic save from the goalkeeper.
But there was nothing he could do moments later as Kizzi headed home Milsom’s corner in the 20th minute.
Down at the other end, Dean Bouzanis produced a low fingertip save to keep out in-form striker Paul Smyth.
Kizzi proved his worth in both boxes with an important block from Smyth’s strike in the second half.
Theo Archibald saw a 20-yard strike fly agonisingly wide as time started to run out for Orient.
Another chance went begging as Otis Khan fired wide as the hosts held on.
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.