Regis Le Bris said his players' measured celebration following their Championship play-off first leg win at Coventry City made him "really proud".
The Black Cats won 2-1 at the CBS Arena on Friday night to give themselves an advantage ahead of Tuesday night's home leg.
Sunderland fans celebrated an important victory - their first at Coventry for 40 years - but the players kept their distance from the away end other than applauding the 2,800 Mackems for their support.
Some Coventry fans felt the Sunderland celebrations were over the top with another 90 minutes to play, but Le Bris said: "It wasn't the case for the players.