The only two undefeated basketball teams in Group B will battle for the opportunity to not play Team USA until the finals.
This game matches the tournament's only unbeaten teams other than the United States, widely expected to repeat as Olympic champion.
Both Spain and Russia will reach the quarterfinal round, but winning the group allows the team to stay on the other side of the bracket from the Americans.
Both teams are coming off one point victories but each view their wins differently.
Spain coach Sergio Scariolo to the media:
"When you lose your focus and concentration, you really get in trouble."
Spain never trailed against Great Britain but crumbled at the end and had to hold on with clutch free-throw shooting by Jose Calderon.
Jose Calderon scored eight of his 19 points in the final 44 seconds against Britain on Thursday, and then eluded defenders frantically trying to foul him to run out the clock and secure a 79-78 win over the host. He is averaging 11.7 points and 2.7 assists.
Pau Gasol had 17 points Thursday and is averaging 19.3 in this tournament to rank seventh among all players. His brother, Marc, matched his own tournament high with 12 points.
Russia (3-0) defeated Brazil 75-74 thanks to Vitaliy Fridzon's 3-pointer with four seconds to play. The Russians blew an 11-point lead and trailed by two before Fridzon hit the shot from the left corner.
Andrei Kirilenko scored 19 points, Timofey Mozgov added 18 and Alexey Shved had 17 with six assists.
Kirilenko is the second-leading scorer in the Olympics at 23.3 points per game, but Shved has been just as big for Russia. He leads all players in the Olympics with 8.3 assists per game while averaging 15.7 points and shooting 51.4 percent from the field.
