David Moyes was left disappointed by the manner of his side's defeat in their final home game of the 2016-17 season.
Sunderland's bright start turned to dust when when Swansea City's Gylfi Sigurdsson launched pin-point free-kick into the area on nine minutes.
The Icelander's delivery caused havoc in the Black Cats' ranks and Fernando Llorente put himself in the mix to head past Jordan Pickford and open the scoring.
Moyes' side fought their way back into the match, Fabio Borini wildly fired over before Lukasz Fabianski did well to smartly turn Jermain Defoe's effort round the post off Billy Jones’ stunned header.
Swansea always looked in control though, and, crucially, got a second on the stroke of half-time, full-back Kyle Naughton lashing home his first Swans goal to seal a seismic three points for the South Wales club in the race for survival.
The second period was one-way traffic, but apart from a stinging Wahbi Khazri drive and a deflected Defoe strike Sunderland failed to muster a real clear-cut chance.
Speaking post-match, Moyes was left disappointed by the defeat.
“It was the most disappointing performance we have had for a long time,” he said.
“Most of the games for the last month or so I’d say there were spells where we played well but I’m not sure we deserved something today.
“Ultimately the first goal was really the turning point.
“Jordan (Pickford) has been superb all year, he hasn’t put a foot wrong for me except for one mistake.
“He has been undoubtedly our best player all season and he just come for something which really wasn’t there for him to come near.
“We have played quite well in games and today both teams set-up with different systems.
“We set-up with three forward players and for the first seven or eight minutes we were the team who had a couple of chances,” he continued.
“The first goal was ultimately going to be really important and they got it.
“We had some disruptions with injuries but the worst thing was we conceded again before half-time and that didn’t allow us to set-up for the second half to get back into the game.
“We didn’t play well enough and overall I can’t say we did enough to deserve anything from the game.”