OKLAHOMA CITY – The worst nightmare of these San Antonio Spurs had unfolded across 48 hours here, frame by frightening frame, and now the sullen patriarchs of this dynasty in winter, Tim Duncan and Gregg Popovich, marched into the dustbowl night flushed with blank faces and burdened minds.

The footprints of Russell Westbrook and Kevin Durant defaced the backs of the Spurs stars on Tuesday night, a Thunder trampling born of a frothing ferocity and the startling spectacle of the superiority that comes with the speed and swiftness and skill. Oklahoma City has become whole again, leaving the Spurs to feel like the dam is back to the brink of bursting, like the future has finally come for them.

Here comes one more telltale Game 5 for Duncan and Manu Ginobili, Tony Parker and Pop in these Western Conference finals. Here comes the roll call on nearly two decades of dramatic victories and dramatic defeats, from four NBA championships to Derek Fisher's .4 shot in 2004 and Ray Allen's corner 3-pointer in 2013, here comes one more moment of truth in the shadows of the Alamo.

"We've done it before," Ginobili told Yahoo Sports late Tuesday night. "We've done it together and found a way to win – and we've lost, too. We are going to spend time talking. We are going to regroup. But this is not automatic. We've been up two and lost it before against them.

"All these things we need to do to have a chance to win, to just have a chance, and, still, they are so athletic."

Ginobili searched for the proper word. "They are…"

He flashed a grim smile and rolled his head on his shoulders. Outside the locker room, on the way to the bus, Ginobili finally said, "Hey, they are good."

"They are really, really good."

Serge Ibaka changed these Western Conference finals, and Westbrook and Durant are threatening to make them their own. Westbrook went full-bore PlayStation on the Spurs, a dizzying, devastating 40 points, 10 assists, five rebounds and five steals on the way to a 105-92 victory. Durant had 31 points and three steals. All those long arms and fleet feet confounded the Spurs, flooding passing lanes and inspiring turmoil. For an offense predicated on precision, these Spurs found themselves blown up over and over by the Thunder's defense.

Beyond the turnovers for touchdowns – the end-to-end chin-ups on the rims – the Spurs temporarily lost a sense of self, a sense of identify. Duncan was a discombobulated mess. Nine points and six rebounds, and an embarrassing encounter with Kendrick Perkins that caused him to lose his composure, get the ball back and get himself swatted despite the Thunder center's modest leaping ability.

After letting loose on a predictable suspect in Perkins, Duncan stalked into a third-quarter timeout, briefly unloading onto a most improbable suspect, Popovich, about how a play had broken down. It happens, and they were over it immediately. Midway through the third period, Popovich considered Game 4 a lost cause and proceeded accordingly. Asked about the thought process that led him to pull his starters midway into the third, Popovich was unapologetic and unequivocal.

"Thursday," he said.

Thursday. Game 5. The Spurs don't pretend they have the solution – or even the wherewithal – to deliver something they haven't been able in six tries this season: A victory over the Thunder with Ibaka on the floor. This is threatening to turn into 2012 again, a 2-0 series edge obliterated with four straight losses to the Durant-Westbrook steamroll.

Popovich can live with losing, but this kind of defeat burrowed within him on Tuesday night. He witnessed an unwise and reckless Spurs team, with something of a death wish.

"All of a sudden we were going to see if Serge could block a shot," Popovich said. "I thought about passing a picture out on the bench. They'd know who Serge was. Instead of hitting open people that are out there, we started attacking the rim unwisely and that turns into blocked shots."

Seven blocked shots conspired with seven more turnovers before the half, and those turn into Westbrook and Durant chin-ups on the rims. Those turn into an impossible formula for a Spurs victory. Those will likely turn into a film session on Wednesday, where Popovich will make his final plea for these Spurs to spare themselves a season suddenly slipping out of grasp.

"We let people push us around," Ginobili said. "They're playing at a different speed, and it's like we are in slow motion. What we need to do is play a game of almost perfection."

Manu Ginobili understands savvy and smarts don't override the genius athletic gifts of Durant and Westbrook and Ibaka. They get the Thunder inside the AT&T Center on Thursday, get a Game 5 that'll ultimately go a great distance in dictating the fate of these Spurs. "So athletic, so long," Ginobili said.

How do you do it now? How do you stop the future when it's come for you in the present? Ginobili has been chasing these big games for a long, long time with Duncan and Parker, and they'll chase one more on Thursday night in Texas. Everyone wanted answers out of him, wanted solutions, and those are scarce in the wake of Ibaka's redemptive return to the season.

In the winter of this dynasty, in the wake of that heartbreaking loss in Miami a year ago, the great San Antonio Spurs see the Thunder coming full force now, see the present and the future as a gathering storm. One more night of reckoning has come for the Spurs, one more moment of truth.