The Black Cats fell behind in the 24th minute after an excellent strike from Morgan Whittaker, who cut in from the right flank to score from the edge of the area.
Plymouth then doubled their lead five minutes before half-time when Finn Azaz was given too much time in the box and beat goalkeeper Anthony Patterson with a low finish.
Here, though, we take a look at the best photos of Sunderland fans throughout the day:
1. Sunderland fans
Sunderland were beaten 2-0 by Plymouth at Home Park – and our cameras were in attendance to capture the action. Photo: Ian Horrocks
2. Sunderland fans
Sunderland were beaten 2-0 by Plymouth at Home Park – and our cameras were in attendance to capture the action. Photo: Ian Horrocks
3. Sunderland fans
Sunderland were beaten 2-0 by Plymouth at Home Park – and our cameras were in attendance to capture the action. Photo: Ian Horrocks
4. Sunderland fans
Sunderland were beaten 2-0 by Plymouth at Home Park – and our cameras were in attendance to capture the action. Photo: Ian Horrocks