SAN ANTONIO — The twisted thing about history is how quickly anniversaries can change meaning. For nine years, May 28 evoked a franchise-haunting what-if. Klay Thompson’s name was whispered in Oklahoma City for a decade following a Game 6 rampage for the ages. Then, a year ago, the Thunder repurposed the date, punching their ticket to return to the NBA Finals. To glory.

This year, May 28 soured again. The Thunder, in the Shai Gilgeous-Alexander era, historically haven’t met the moment when summoned for a Game 6. Thursday’s 118-91 thrashing, though, invited more than a Game 7. It created an inflection point.

Oklahoma City’s potential dynasty faces its most serious threat to date.

The players recognize the stakes. All-NBA forward Jalen Williams, after a season thwarted by injuries, hurried to return for Game 6 after missing the previous four with a left hamstring injury. Gilgeous-Alexander, after being stifled in these Western Conference finals, framed OKC’s stark reality.

Game 7, he said, is the biggest of his career.

“It’s the next game,” he reasoned. “And if I lose, my season’s over.”

He’ll continue holding his tongue about San Antonio star Victor Wembanyama and game-plan items, though few secrets remain in a series so meticulous and taxing. It’s already revealed several truths.

No team is better equipped to defend SGA since his reign as an All-Star began. And when Wembanyama resembles the best player on the floor, as he did in a 28-point, 10-rebound performance on Thursday, a win is all but guaranteed.

SGA, who finished with 15 points on Thursday, is more mindful of who’s manning the rim than ever. He’s launching floaters and sidesteps that he previously held too much control over to settle for. He’s changing the trajectory of shots to prepare for a slender man’s reach. He’s trying to shed an obsessive, physical defender like Stephon Castle with jumpers that hold a degree of difficulty too demanding for anyone — even a back-to-back MVP.

In six games, he’s averaging 24.3 points and 8.8 assists while shooting 40.9 percent on 2-pointers and 26.1 percent from 3. He was a minus-28 in Game 6.

“It’s too late to abandon my work and abandon my game and who I am,” SGA said. “I gotta trust it and live or die by it.”

In this series, Wembanyama is toggling between being extraterrestrial and getting buried by physicality. At his best, his wingspan lets him parachute into plays, and he finishes dunks from his hip. On Thursday, he relied on his jumper.

He hit his first three 3s, the third while moving, guard-like and game-breaking.

“I think he’s comfortable,” Gilgeous-Alexander said. “And when he’s comfortable, he’s good. Like really, really good.”

San Antonio’s defense produced a third quarter that would send a shiver down the spines of SGA’s predecessors in Oklahoma City.

OKC scored 13 points in 12 minutes. It shot 6 of 28, missing all eight of its 3-point attempts. It conceded a 27-6 run, and a historically greedy defense could hardly string together two remarkable possessions.

Backup Spurs center Luke Kornet’s minutes have offered an opening this series — mostly a break from Wembanyama’s wrath. The Thunder lost Kornet’s four third-quarter minutes by 11.

Disaster struck for a team that survived rounds to that point: Dylan Harper’s near-immaculate first half, Devin Vassell’s incredible shooting and a block that left 7-foot-1 big man Chet Holmgren unsettled.

“We had a chance to turn the game, but you’ve gotta turn the game,” Thunder coach Mark Daigneault said. “You can’t wait for the game to turn.”

There is a compounding weight to quarters like that. The noise they produce. The message they send. San Antonio signaled all it needed to before the period — and this series — finished.

The Thunder reserves, who’ve already won games in this series, needed to play at an impossible level. Because OKC’s stars are limited, SGA is smothered and bothered. This matchup scrambles Holmgren’s impact. Williams, Daigneault acknowledged, isn’t 100 percent healthy, hellbent on returning in an “insulated role.” He produced one point and two turnovers in 10 minutes, a minus-18, appearing to lack the mobility that underpins his value.

Meanwhile, veteran Alex Caruso tallied seven points, his second-fewest in any game this round. Jared McCain made two of his eight attempts inside the arc. Jaylin Williams and Lu Dort combined to shoot 1 of 13 from beyond the 3-point arc.

Defense and depth brought the Thunder here. They oiled the gears of a machine as regular-season injuries piled up. The attributes and their sustainability motioned toward a dynasty.

However, in the planning of this dynasty, a Western Conference foil wasn’t predicted so soon. A tandem of a shot blocker and point-of-attack defenders who could muzzle stars. A superstar who could infiltrate OKC’s historic defense. San Antonio, experience be damned, might have the best weapon wheel of any team that’s taken the Thunder the distance.

“Not much feels different just from a standpoint of it (being) a Game 7,” veteran Alex Caruso said. “It’s one game or you’re going home. It’s more of a focus, I think, on us. Game 7 has gotta be about us.”

The Thunder’s history on May 28 is troubled and tangled. Their history with Game 7s, a couple of defining moments for this group versus the Denver Nuggets and Indiana Pacers a year ago, suggests they can still shape their fate. Their place in these dynastic discussions depends on it.