Che Adams scored his first goal for Southampton, a year after joining the club, with a stunning long-range strike as they beat Manchester City 1-0 to condemn Pep Guardiola's side to a third successive away loss in the Premier League.
Adams signed for Saints from Birmingham City for a reported 15 million pounds ($18.72 million) in July, 2019, and had failed to score in his previous 24 league appearances for the team.
Second-placed City responded with a wave of attacks but came up against Southampton keeper Alex McCarthy in inspired form.
After the break, City's pressure intensified and Guardiola brought on Kevin De Bruyne and Phil Foden as he tried to find a way through a Southampton side with the worst home record in the Premier League this season.
"The lads dug in deep at the end and we got a well deserved three points," said Adams. "We're based on Man City, that's how we play football and we've been doing it all season long. It's nice to score anytime, thankfully it's come today -- just in time."
Southampton manager Ralph Hasenhuettl hailed the victory as his side's best home performance in his time at the club and said they had been aware of the chance to expose Ederson.
"If you have a goalkeeper playing like him, as a libero, it is normal that he isn't always in his goal. Our goal was to be clinical and quick in your mind, and it was an unbelievable first touch and goal from Che," he said.
City stay on 66 points, 23 adrift of Liverpool and eight clear of third-placed Leicester City. Guardiola, who took over at The Etihad in 2016, has never lost three straight away league games before in his managerial career.
"We played really well, but made a few mistakes in our box and got punished," said the Spaniard. "Afterwards we created a lot but couldn't score and that's a little bit the story of our season in the Premier League. We played really, really well."