Defender Ben Goodliffe scored the only goal of the game as Sutton beat Hartlepool 1-0 in the EFL New Boys Battle at Gander Green Lane.
The United States defeated Pools to claim the National League title in May as they reached the Soccer League for the first time in their 123-year history.
Group goalie Ben Killip made two good saves to stop Enzio Boldewijn first and then Saturday’s two-goal hero Richie Bennett in the first half.
But the hosts got the deserved opener as Goodliffe made it home to the far post.
Sutton’s skipper, Craig Eastmond, secured the lead at halftime by clearing the lead from Time Odusina.
American stopper Dean Bouzanis made two nice saves to keep David Ferguson and Olufela Olomola out of the lead as the rain fell after the break.
At the other end, the sprawling Killip did well to deny David Ajiboye with 15 minutes remaining.
And frustrations boiled over when Pools boss Dave Challinor was booked for protesting with the fourth official.