Torino won their race against time to register Josip Brekalo, who rushed through his medical to complete the move from Wolfsburg.
It is a loan for €1m with option to buy at the end of the season for a further €11m.
The transfer had been in some doubt, as the Croatia international only landed at the airport in Turin with a private jet this afternoon.
He was whisked away to undergo medical tests and got the paperwork completed too, all within an hour.
The 23-year-old is a left-sided winger who had also been close to Lazio earlier in the summer.
Brekalo has four goals in 27 senior caps for Croatia.
Wolfsburg paid €10m to purchase the player from Dinamo Zagreb in 2016 and he has been a regular there since returning from a loan spell at VfB Stuttgart from January to December 2017.
Torino have been very active on transfer deadline day, also bringing in Dennis Praet from Leicester City and David Zima from Slavia Prague.
Alessio Rosa also arrived on loan from Atalanta.