The Black Cats dominated large spells but couldn’t make their superiority pay, while the late dismissal of Tom Flanagan saw them forced to defend in the dying stages.
So who emerged with some credit from the trip to London, and who has work to do?
Scroll down and click through the pages as Phil Smith dishes out his player ratings:
1. Lee Burge
Barely tested by a Charlton side that failed to produce much on the ball for the majority of the contest. 6 Photo: Frank Reid
2. Jordan Willis
Another controlled display from the right-sided defender, who did well throughout and offered a threat going forward, particularly in the first half. 7 Photo: Frank Reid
3. Bailey Wright
Looked completely at ease yet again for the vast majority of the contest, though one of his few lost headers came as Aneke forced the red card from Flanagan. Remarkably, though, this was his seventh clean sheet in nine league games for the club. 6 Photo: Frank Reid
4. Tom Flanagan
Had rarely been troubled defensively in another assured display but the defence was caught out seemingly from nowhere. It was a soft red, a trip rather than a challenge of any malice. Washington, though, was through on goal and the referee had little choice but to produce a red. 5 Photo: Frank Reid