Sutton clinched only their second away Sky Bet League Two win of the season with second-half goals from Joe Kizzi and Rob Milsom earning a 2-1 triumph at struggling Crawley.
United’s first victory on the road since the middle of October left new Crawley boss Matty Etherington with two defeats in his opening three games in charge.
Etherington stressed going into the game that he wanted to see a performance that “gets the crowd going” after criticising his side for being “awful” in the 2-0 home defeat by Hartlepool.
Sutton were forced into a late change with Donovan Wilson injuring himself in the warm-up and being replaced by Josh Neufville.
Neufville should have done better just after the half-hour mark when he put the ball wide after a surging run deep into the area by Will Randall.
Crawley keeper Ellery Balcombe was called into action for the first time just before the break when he held Harry Beautyman’s header after a teasing cross from Milsom.
The Reds had a scare immediately after the interval when top scorer Randall flashed an angled shot narrowly wide in front of the travelling fans.
Sutton broke the deadlock on 61 minutes when Kizzi fired his first goal of the season from close range after keeper Balcombe parried a shot from Omar Bugiel.
It got better for the visitors nine minutes later when former Crawley defender Milsom made it 2-0 from the penalty spot after veteran Tony Craig had brought down Bugiel.
Substitute Aramide Oteh fired home from close range from Dom Telford’s assist in the last minute of stoppage time for Crawley but it was no more than a consolation.