Kevin Durant, left, celebrates with Devin Booker during the United States’ 95-81 victory over Spain in an Olympics men’s basketball quarterfinal Tuesday in Saitama, Japan. AP Photo/Eric Gay

SAITAMA, Japan — Back and forth they went, the three-time defending Olympic champions from the U.S. on one side, the reigning Basketball World Cup champions from Spain on the other.

The difference: The Americans had Kevin Durant.

He’s never gone to the Olympics and not won gold — and clearly, doesn’t plan on that changing. Durant scored 29 points to keep his quest for a third Olympic title alive, and the Americans are headed to the medal round after ousting Spain 95-81 on Tuesday in a quarterfinal matchup at the Tokyo Games.

“We’ve just got to finish it. Got to finish it,” Durant said. “We’re supposed to be here. For us, it’s about getting the gold.”

Jayson Tatum scored 13 and Jrue Holiday added 12 for the U.S., which will play either Australia or Argentina in the semifinals on Thursday. The Americans also gave themselves the chance of extending a streak like none other in Olympic basketball history — in all 18 of their previous Olympic men’s basketball appearances, they’ve gone home with a medal.

“It was a wonderful game in the sense that we feel absolutely great about the victory, knowing full well there’s a lot of work to be done,” U.S. coach Gregg Popovich said. “We played a terrific basketball team.”

Ricky Rubio was brilliant for Spain, scoring 38 points — a Spanish men’s Olympic record, and the most ever scored by a U.S. men’s Olympic opponent, topping the mark of 35 by Puerto Rico’s Butch Lee in 1976. Sergio Rodriguez added 16 and Willy Hernangomez scored 10 for Spain.

Damian Lillard scored 11 and Zach LaVine added 10 for the U.S.

“Right now, there is no time for disappointment and no time for any other bit of feeling,” Spain coach Sergio Scariolo said. “We are competitors and we lost the quarterfinal, but we know we played against an unbelievable team.”

It wasn’t easy, and rarely is against Spain. This was the fifth time the teams — the top two men’s programs in the most recent FIBA world rankings, the U.S. at No. 1 and Spain No. 2 — had met in the Olympic quarterfinals or later since 2004. The U.S. is now 5-0 in those games, but the margin of victory in those is a close-by-American-Olympic-standards: 9.2 points.

And this one was no different. Spain actually led by 10 in the second quarter, before the U.S. went on what became a 36-10 run over the next nine minutes to take control for good.

“It was a huge boost,” Durant said. “We didn’t want to go into the half down double digits. … We knew we didn’t want to get down big against this team.”

Spain had won three consecutive Olympic medals, taking silvers after losing to the U.S. in the gold-medal games in 2008 and 2012, followed by a bronze in 2016 after falling to the U.S. in the semifinals. And this may be the last time that the Spanish roster has some of its longtime mainstays; Pau Gasol is 41, other top players like Marc Gasol and Rudy Fernandez are much closer to the end than the beginning, and this might have been Spain’s best chance to beat the U.S. at the Olympics.

“I think it’s time for somebody else to enjoy the ride,” Marc Gasol said, indicating he’s playing for Spain for the final time, after a game where he and his brother both went scoreless — an unthinkable concept in Spanish basketball for two decades. “I think it’s time for me to get off the ride and for some young guys to step on and enjoy it.”

Spain got down seven early, then simply did whatever it wanted against the U.S. for a 10-minute stretch of the first half. It was a 29-12 run by the time it was over, a burst that turned a 17-10 early deficit into a 39-29 lead with 3:25 left until halftime.

Spain shot 13 for 22 during that stretch, the U.S. just 5 for 22 — missing 12 of its last 13 shots in the run. But just when it looked like the Americans were in big trouble, it was their turn to rally.

“We just needed to respond,” Tatum said. “It was a time, not to get worried, but to raise our sense of urgency.”

And that’s what they did. A 14-4 U.S. run to close the half made it a 43-43 game at intermission, the burst capped by seven consecutive points over the final 70 seconds. With that, it was a 20-minute game to decide who would play for medals and who would be going home earlier than planned.

The Americans didn’t trail again.

“A team with so much firepower, you learn,” Marc Gasol said. “You learn.”

The U.S. opened the second half on a 15-4 run — making it a 22-4 run going back to late in the second quarter — and went on to lead by as many as 16 before taking a 69-63 edge into the fourth. The lead held up, and the medal round awaits.

“We’re in a good spot right now,” Durant said.