Salford took advantage of Donovan Wilson's dismissal by scoring twice in the last 11 minutes to inflict Sutton's first home league defeat of the season with a 2-1 victory.
Although Sutton had more of the play in the first half, it was Salford who had the best chance when Callum Hendry stabbed Luke Bolton's cross straight at Sutton's debutant goalkeeper Lewis Ward.
However, Louis John came close for the home side when he headed just wide from Will Randall's free-kick.
The dangerous Randall was forced off at half-time through injury and, just after the hour mark, it was Randall's replacement, Enzio Boldewijn, who created the breakthrough when his fine cross was volleyed in at the far post by Josh Neufville.
But five minutes later Wilson was sent off following an off-the-ball incident and Salford took full advantage.
Matty Lund equalised after being set up by Hendry and Ryan Watson scored the winner with three minutes left.
In the last minute Jacob Chapman saved at full stretch from Kylian Kouassi to deny the hosts a point.