The Black Cats dominated possession for large spells but couldn't find a breakthrough against a compact Bluebirds defence.
Cardiff then nicked a late winner when defender Mark McGuinness headed home Ryan Wintle’s corner three minutes from time.
Here, though, we take a look at the best photos of fans throughout the day courtesy of Frank Reid:
1. Sunderland supporters
Sunderland were beaten 1-0 by Cardiff City at the Stadium of Light – with our cameras in attendance to capture the action. Photo: Frank Reid
2. Sunderland supporters
Sunderland were beaten 1-0 by Cardiff City at the Stadium of Light – with our cameras in attendance to capture the action. Photo: Frank Reid
3. Sunderland supporters
Sunderland were beaten 1-0 by Cardiff City at the Stadium of Light – with our cameras in attendance to capture the action. Photo: Frank Reid
4. Sunderland supporters
Sunderland were beaten 1-0 by Cardiff City at the Stadium of Light – with our cameras in attendance to capture the action. Photo: Frank Reid