With Kevin Durant leading the way with 30 points and LeBron James and Kobe Bryant backing him up, the USA retained their Olympic title in a repeat of the closely-fought 2008 final in Beijing.
Spain, relying on the inside game of Pau Gasol and the outside shooting of Juan-Carlos Navarro, gave the powerhouse USA team their most serious test after the Americans had won their first seven games by an average margin of 35 points.
"The closer the game got the more intense we got, the more focused we got," said Bryant.
Spain, featuring a towering frontcourt with Pau Gasol, his younger brother Marc Gasol and Serge Ibaka camping out under the basket, were much bigger in the lane but could not quite match the USA scoring punch in the end.
Pau Gasol, who has won two NBA titles as a team mate of Bryant's on the NBA Los Angeles Lakers, glowered at Bryant after he was fouled at one point, but at the end of the game the two had a long hug on the court.
"They're very talented, very gifted players. They can score in bunches and you have to give them credit," Gasol said.
"I feel proud of our silver."
Both teams rushed the ball upcourt in non-stop action to the roaring delight of the 20,000 fans packed into North Greenwich Arena and were separated by just one point at halftime at 59-58.
The USA were still clinging to their one-point lead at 83-82 going into the fourth quarter before point guard Chris Paul and James took control at the start of the final quarter to give the United States some breathing room.
The Americans built a nine-point lead at 95-86 midway through the fourth, with Durant and Bryant taking turns scoring the ball.
After Spain's Juan-Carlos Navarro sank a jumper and Rudy Fernandez tapped in a follow shot on a fast break, James took the spotlight with a drive he finished with a volatile slam and a three-pointer that restored the USA cushion.
James, who added London gold to his NBA Most Valuable Player award, his NBA Finals MVP and the NBA title he won with the Miami Heat, had 19 points as second-high scorer for the Americans.
"We just wanted to continue to share the ball, continue to make plays," said James, who also had a team-high four assists.
"But it starts with stops. If we don't get defensive stops we don't build that lead. It's a one-point lead going into the fourth and we were able to build that lead and that's what it's about."
With 15 three-pointers, the USA more than doubled the seven long-range shots made by Spain, who had to work harder to keep up with the American sharpshooters.
Gasol, who scored the first 13 points for his team at the start of the third quarter to help them take a 71-70 lead, topped the scoring list for Spain with 24 points.
The first half of the game was marked by some rough physical play with several hard fouls taken. Each team was assessed an unsportsmanlike penalty and the USA bench was warned they would be penalised if they continued to complain.
"It was a beautiful game of basketball," said the Memphis Grizzlies' Marc Gasol, who was hit with his fourth foul midway through the second quarter yet still scored 17 points for Spain.
"Our team did a great job out there. We just couldn't pull it off."
Navarro, who scored 14 points in the first quarter to open up the lane for Gasol to operate in, finished with 21 points.
"We know Spain is a great team. They match up well with us. We match up well with them," said James, referring to the size advantage held by Spain and the edge in quickness and scoring power enjoyed by the Americans.
"They wanted redemption. We are just happy we were able to make enough plays and come through."
- Pau Gasol
- Marc Gasol
- Kobe Bryant
- LeBron James