Southampton have signed striker Guido Carrillo for a reported fee of £19.2 million from Monaco.
The 26-year-old has penned a contract until 2021 and will link up again with Saints boss Mauricio Pellegrino, who he played under at Estudiantes.
Pellegrino had identified his fellow Argentinian as the solution to his team's struggles in the final third, where a lack of goals has made them candidates for relegation.
Saints reportedly beat Premier League rivals Crystal Palace to Carrillo's signature and the forward hailed Pellegrino as a major reason for choosing St Mary's.
Carrillo told the club's website: "I'm very happy. It's a great feeling to be a part of this club.
"Lots of things attracted me. I know Southampton from watching the Premier League from when I was small, I've always regarded it as the most important league in the world.
"I obviously know the coaching staff, I've worked with them in Argentina and I also spoke with some players who were former teammates in Argentina, who are now playing in the Premier League.
"They told me all about the club and gave it a shining reference. Therefore, I had no doubts when I took the decision.''
Carrillo joined Monaco from Estudiantes in 2015 and scored 15 goals in 65 Ligue 1 appearances, of which only 22 were starts.
Southampton's vice-chairman of football Les Reed said: "A huge amount of work has gone in to completing this transfer, and we are thrilled that we have now been able to push it through to completion.''
Southampton also hope to sign Dutch winger Quincy Promes from Spartak Moscow for what would be a club-record £30 million.
When asked at his press conference earlier on Thursday if they had moved closer to bringing in the 26-year-old, Pellegrino said: "I don't know. We are waiting for some answers. I don't think [a fee has been agreed].
"Still we have another five or six days to keep working and pushing and after we will see.
"He's an important player but there are a lot of players I would like to bring in. He's one of the players we were following and it's one possibility.''
On Saturday they host Watford in the fourth round of the FA Cup. Shane Long and Maya Yoshida will be available but Charlie Austin remains sidelined with a hamstring injury.
Sam McQueen faces a late fitness test, while Ryan Bertrand is suffering from flu.