Spain take on unbeaten Russia looking to climb to the top of Group E.
The world champions bounced back from their defeat to Croatia with an emphatic triumph against Greece.
Pepu Hernandez's men face another challenge on Sunday's against a team that is showing no signs of slowing down.
Spain last met Russia two years ago in the group stages at the EuroBasket in Belgrade and won 89-77 although the Russians were without Andrei Kirilenko.
Pau Gasol will need to play a big part in stopping Andrei Kirilenko.
Key match-up: Andrei Kirilenko v Pau Gasol.
Portugal got steamrolled by Andrei Kirilenko last time out and then raved about his ability to dominate on the boards but also get out on the fastbreak.
Kirilenko will not find it so easy against a big, strong frontline that is led by Pau Gasol.
Russia went unbeaten in the group stage, which included an impressive win over EuroBasket 2005 winners Greece, but the game against the world champions is the one that will let everyone know if David Blatt’s team is for real.
Gasol knows Spain will make a mistake if they focus only on Kirilenko and fail to close down the vastly underrated Victor Kryapa and JR Holden.
"Russia is not Kirilenko and 11 more," said Gasol.
"But he does help out in every stage of the game. He contributes on defense, blocks shots, rebounds, assists and knows how to play. You need to get him out of the game."
Key Stats: David Blatt's men didn’t run away from Portugal as they should have and one reason was their poor free throw shooting 15 of 27 (56%).
Russia, led by Kirilenko (11.5 average), have outrebounded all of their opponents so far while Spain lost that battle against Croatia and Greece.
X-Factor: Zakhar Pashutin came off the bench against Portugal for Russia and helped steady the nerves for Russia.
The 1.96m guard is 33 years old with a lot of national team experience, and with Spain boasting the best backcourt in the world of Jose Calderon, Juan Carlos Navarro, Carlos Cabezas, Sergio Rodriguez and Rudy Fernandez – Russia coach Blatt needs Pashutin to have a big game.
Speaking out: "Spain's a whole other animal. They're the home team. They have the home crowd, they're the reigning world champions and now, ironically, being that they're one loss down, they're going to be more motivated than ever. They were motivated as hell already. So that's about as dangerous a team as you're going to meet - a team that's good, one that's hungry and one that's in need of wins"- Russia coach David Blatt.