OAKLAND (California) • Composure and firepower were two staples of the San Antonio Spurs teams that won five National Basketball Association (NBA) championships in the Tim Duncan era.

On Sunday, those qualities belonged to the new Western power, the Golden State Warriors, especially after the Spurs lost their best player, Kawhi Leonard, to an injury.

The Warriors went on an 18-0 run immediately after Leonard left the game in the third quarter and then had just enough left in the tank at the end to finish off a come-from-behind 113-111 victory over the Spurs in Game One of the Western Conference Finals.

"When I looked in their eyes, I felt they believed," Warriors assistant coach Mike Brown said after watching his club rally from 25 points down in the first half. "With the team that we have, the veteran guys, their composure, and then the firepower, we know that we're always going to have a chance."

Game Two in the best-of-seven series is tomorrow (Singapore time), also on the Warriors' home court.

Whether the Spurs will have Leonard available is unknown. He suffered a recurrence of his left-ankle injury after torching Golden State for 26 points in 24 minutes.

San Antonio outscored Golden State by 21 points while Leonard was on the floor.

"Just very painful because I tweaked it before," Leonard said of the injury. "It's hard to tell (about Game Two). I definitely couldn't go (the rest of Sunday's game). But we'll see how I get better each day."

Leonard said he thought Zaza Pachulia's play - he stepped under Leonard on a long jump shot - was not intentional.

"It was huge," Spurs veteran Manu Ginobili said of Leonard's absence. "We were doing really well. When he went down, the Warriors were starting to pick up, to feel good about themselves, to increase the pressure on everybody, and that's when we struggled, because we couldn't have the guy that we run those plays (through) and get them off their pressure."

Rallying from a 20-point half-time deficit, the third-biggest comeback in NBA history, the Warriors got a game-high 40 points from Stephen Curry and 34 from Kevin Durant.

The Spurs retained a 106-103 lead with less than two minutes left to play before a key sequence set up the Warriors' game-winning finish.

Curry and Durant both missed three-pointers, but, where a rebound would have given the Spurs the lead - Golden State outrebounded San Antonio 43-37 - and the ball with the clock winding down, the Warriors ran down both rebounds, setting up a Curry trey that tied the game with 1min 48sec left. The Spurs never led again.

"I thought the rebounding really hurt us, as evidenced by (that sequence)," Spurs coach Gregg Popovich said. "It was kind of indicative of what kind of mistakes we might have made. Great effort, tough loss, great opportunity, and we let it slip away."

REUTERS

GOLDEN STATE V SAN ANTONIO

Game Two: Singtel TV Ch110, tomorrow, 8.30am