The Thunder-Rocket series is proving two things, at least on the Oklahoma City side.

How good Kevin Durant is.

And how good Russell Westbrook is.

The Rockets clubbed the Thunder 107-100 — it wasn't that close — in Game 5 Wednesday night, and everyone in Thunder blue is thinking the same thing.

Uh-oh.

History could be in the making. No NBA team ever has won a playoff series after trailing three games to none, but the Rockets are halfway there. And headed home to Houston.

“Go home for Game 6,” said Rocket star James Harden, who posted a cool 31 points on 10-of-16 shooting. “It should be interesting.”

Nothing but interesting. Even in victory, the Thunder has seemed completely lost without Westbrook, the mercurial point guard who suffered a season-ending knee injury in Game 2.

Without Westbrook, the Thunder load is completely on Durant, who was mighty for three quarters Wednesday night, with 36 points on 11-of-18 shooting.

But let it be noted that the Thunder still trailed 87-75 after those three quarters. You can't win with one player carrying such a big load, a lesson taught in yesteryear by Wilt Chamberlain teams and taught in more recent vintage by LeBron James in Cleveland.

The Rockets are hounding Durant vigorously. Face-guarding him. Double-teaming him. Picking him up full court.

“They don't really care about anybody else on the team,” Durant said of the Rocket defense.

And it's mostly working. Durant finally slumped, with a scoreless fourth quarter. And Durant's troops didn't produce in Game 5. At least not until it was too late.

The Thunder shot just 41.9 percent from the field. After Reggie Jackson made a 3-pointer to tie the game 5-5, the Thunder missed 13 straight 3-pointers, on a night when the Houstons were filling it up from beyond the arc.

“Bad combination when one team makes threes and another doesn't,” said Scotty Brooks, who now coaches a team that is in danger of the NBA's greatest collapse.

Without Westbrook, the Thunder has had three straight games with little offensive flow, except for Durant magic.

The Thunder is playing like a football team trying to win with a second-team quarterback. Everything out of sync.

And that's no indictment of Reggie Jackson, the point guard who replaced Westbrook in the lineup. Jackson has played reasonably well and had 20 points Wednesday night.

Nothing about this offense looks like it did when Westbrook had the reins. Everything is a struggle.

“Tonight, we were moving, we were cutting, but we started missing shots, it messed with us,” Durant said. “We're going to have wide open shots. We gotta knock ‘em down. We'll be fine.”