One-point victories in their most recent games clinched Olympic quarterfinal berths for Russia and Spain.
Even so, their next game in the preliminary round is far from meaningless.
These teams square off Saturday in a matchup which could determine the No. 1 seed in Group B and the likelihood of avoiding the gold-medal favorite until the final.
This game matches the tournament's only unbeaten teams other than the United States, widely expected to repeat as Olympic champion. The Russia-Spain winner will be alone atop Group B with one more preliminary game remaining, and the team which ends up in first place wouldn't have to face Team USA until a potential gold-medal game - assuming the U.S. goes on to win Group A.
Both Russia and Spain barely managed to remain unbeaten Thursday while clinching top-four spots in Group B to lock up places in the quarters.
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.
"I went with the best option I thought we had," said David Blatt, Russia's American-born coach. "He made the shot. Good for him. He made his coach look good."
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.
Shved's point guard counterpart also has played a vital role for Spain (3-0).
Jose Calderon scored eight of his 19 points in the final 44 seconds against Britain on Thursday, 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.
Both teams feature several NBA players and have showed the ability to play well collectively. Spain and Russia rank second and third in this tournament in assists, respectively.
Pau Gasol, the leading scorer at the past two Summer Games, 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.
"It has been hard but beautiful. The important thing is that we got our third victory," Marc Gasol told FIBA's official website. "There is still a lot of room for improvement. We have to improve on a lot of things."
Spain should be able to compete with the physicality of Russia, as the Spaniards have been able to control the glass throughout their pool games and are tied for the most rebounds per contest with the United States.
However, Spain could be without its captain. The status of Juan Carlos Navarro, who scored 14 points in a tournament-opening win over China, remains uncertain after he missed the last two games with a foot injury.
These countries haven't met since splitting two games in 2007.
