Kevin Durant said Team USA have "got to finish it" after battling past Spain to reach the Olympic semi-finals.

The Brooklyn Nets star poured in a team-high 29 points as the United States won 95-81 at the Saitama Super Arena, bolstering their gold medal hopes.

It was far from an easy assignment, and nor was it always entirely convincing from the US team, who trailed 39-29 with 3:25 of the second quarter remaining.

They rallied impressively, however, to draw level at 43-43 at the halfway point, and Spain never led again.

"We started making shots there in the second quarter. Once we see that ball going into the rim, that put all of us at ease," Durant said.

"Our defence was a little better, a little tighter, we rebounded better after that. And guys just got more comfortable shooting the basketball.

"We drove it to the rim at the end of that second and were able to get our rhythm back a little bit. I like how we played in that second quarter, from the end of the second quarter all the way to finish the game, and that's how we're gonna need to play going forward.

"It was a huge boost. 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."

Ricky Rubio plundered 38 points for Spain, with the Minnesota Timberwolves man shooting 13-of-20 from the field. That gave him the highest score by a Spain men's player in an Olympic game, beating the 37 points that Pau Gasol scored against China in 2004.

Rubio also drained four of his seven shots from three-point range, the same as Durant, but USA's 22-6 run at the start of the third quarter took the game away from Spain.

The Spaniards briefly got back to just four points behind, in the early moments of the fourth quarter, yet despite their overall 42-32 dominance on the boards, they were found wanting elsewhere.

USA coach Gregg Popovich said: "I feel great about the victory knowing full well there is a lot of work to be done. We played a terrific basketball team.

"To play that team and go down by nine or 10 and stay in and find a way to win is very satisfying."

Durant feels the team are ready to step up a level, now they are through to the final four.

The pre-Olympics defeats to Australia and Nigeria no longer matter, nor does the loss to France in the Tokyo 2020 group stage.

"I love how we stuck with it throughout this whole period of time and guys started figuring out what we need to do," Durant said.

"You've just got to finish it. We're supposed to be here. For us it's about getting a gold."