Plymouth Argyle claimed a long-awaited first away victory of the season as Morgan Whittaker struck the only goal against former club Swansea City.
Whittaker scored his 17th goal of the season with a precise first-half finish and Plymouth held on to ensure Luke Williams' wait for a first Swansea City league win continues.
Williams will feel frustrated that Swansea did not get at least a point from the game, however, after Jamie Paterson, Jerry Yates and Charlie Patino missed golden opportunities to level and Liam Cullen struck the bar with a spectacular late drive.
Plymouth's maiden Championship away win of the campaign came at the 15th attempt, and was their first in the second tier since 2010, when they last played at this level.
The landmark triumph continues Ian Foster's impressive start to life as Plymouth boss, with the club unbeaten in five games in all competitions since he took charge on 5 January.
But for Williams, who was appointed by Swansea on the same day, it has been a more challenging opening spell.
This was a fourth successive defeat in all competitions, with Swansea taking only one point from four league games since Williams arrived from Notts County.
His side remain 17th in the table - and just five points clear of the drop zone - with Plymouth now three points better off in 15th.
Plymouth's quest to register a first away league victory since they won a League One game at Port Vale last May might have got off to the worst possible start had Swansea defender Ben Cabango not lashed an early chance over the bar.
But Whittaker, who made only five league starts during his time at Swansea, looked the game's most menacing player early on.
He almost broke the deadlock when a long clearance was not dealt with by the home defence, only for goalkeeper Carl Rushworth to tip Whittaker's dipping half-volley over the bar.
From the short corner which followed, Adam Forshaw was allowed time and space to pick out Whittaker who, while equally untroubled by Swansea defenders, sent a crisp, first-time shot low into the net.
If Whittaker was the man most likely for Plymouth, Ronald was Swansea's biggest threat on his full debut following his January move to Wales.
The Brazilian winger should have had a first Swansea assist when he pulled the ball back for Paterson, only for his shot to sail over the top.
Ronald then delivered a perfect cross for Yates, but his first-time effort hit the onrushing Conor Hazard and ricocheted over the bar.
Another Ronald cross early in the second half produced another chance for Yates, but this time his near-post header rolled wide.
Plymouth had opportunities to finish Swansea off, with Ryan Hardie, Bali Mumba and Mickel Miller all miscuing attempts before another Miller effort flashed wide.
Swansea then mounted a final push for a leveller, with deadline-day recruit Przemyslaw Placheta firing over before fellow substitute Cullen was denied a tap-in as Hazard pawed the ball out from under his bar.
Cullen then came within inches with of an equaliser when his 20-yard drive hit the woodwork, before Patino shot straight at Hazard from point-blank range in stoppage time as Plymouth clung on to take all three points.
Swansea head coach Luke Williams:
"I am frustrated that we didn't turn really good actions into goals. When you create 19 chances and at least four of them are in the six-yard box, there's not an excuse to not win the game.
"What is that's wrong with those chances? For me, nothing. It's just concentration, finish the action correctly and we'll win the game of football.
"The goal we conceded, we lose concentration again from a long ball forward. Whittaker hits the shot that leads to the corner. Then from the corner we switch off, player gets blocked and it's a good strike.
"I think everyone knew these fixtures were coming up. I just concentrate on trying to make the team play really well to give themselves the best chance of winning a game of football.
"Today we gave ourselves a really good chance but then you have to take the chance."
Plymouth Argyle head coach Ian Foster:
"In my short time at the club, we have had to find a way of winning on the road. Sometimes you have to make sacrifices in order to do that.
"Our challenge is to maintain the attacking threat we have but from a really solid defensive structure.
"That was probably a perfect performance today in terms of doing that.
"Of course at times we have to get better with the ball, but we have to start somewhere. We have to get the points on the board."