Zenit St Petersburg have signed FC Porto striker Hulk and Benfica midfielder Axel Witsel in an €80 million double swoop.
Brazil international Hulk and Belgium international Witsel have both signed five-year contracts with the big-spending Russian club. Reuters report that Zenit paid €40 million for each player.
Zenit spokesman Dmitry Tsimmerman said: "It's now official. Both players had signed five-year deals."
Hulk had long been linked with a switch to Chelsea, and had also interested Tottenham, but Porto's asking price proved a stumbling block for the Premier League clubs.
The 26-year-old striker scored 54 goals in 103 league matches to help Porto to win three Portuguese league titles and the 2011 Europa League trophy after joining from Japanese J-League side Tokyo Verdy in 2008.
Highly-rated midfielder Witsel, 23, only joined Portuguese side Benfica in 2011 from his hometown club Standard Liege, where he started his career in 2006.
Zenit, drawn in Champions League Group C along with AC Milan, Anderlecht and Malaga, will be able to use both players in Europe's flagship competition.
"We were trying to sign them before the September 3 deadline for the Champions League so they can play for us in that competition as well as the Russian league," Tsimmerman said.
The Russian transfer window remains open for another week and Zenit's backers Gazprom are expected to fund more signings.