HOUSTON -- Postseason series tend to morph over time as teams scheme, adjust and then re-adjust to fit the terms of engagement. But what the Houston Rockets managed on Sunday night ran contrary to what anyone could have anticipated.

Buoyed by the all-around tenacity of guard Patrick Beverley plus a surprisingly overwhelming advantage on the glass and in the paint, the Rockets blitzed the Oklahoma City Thunder 118-87 in Game 1 of their Western Conference first-round series at Toyota Center.

Game 2 is Wednesday night at Toyota Center.

Beverley scored a playoff-career-high 21 points and added 10 rebounds plus two steals to steer the ship until MVP candidate James Harden got untracked.

Harden missed all six of his 3-point attempts in the first half but rebounded to shoot 4 of 8 from the field and 8 of 8 from the free-throw line while scoring 19 of his 37 points following the intermission. Harden added nine assists and seven boards.

The Thunder closed the season leading the league in rebounding rate, yet the Rockets finished with a 56-41 advantage on the glass and a 62-38 edge on points in the paint. Houston coasted to victory despite missing 23 of 33 3-point attempts.

"We kept preaching that, that we're not going to shoot the ball well all the time so we've got to find other ways to win," Harden said. "We've just got to figure it out. Tonight was a game where defensively we played really, really well. We didn't shoot the ball well, but we got into the paint and we finished (at the rim)."

Thunder guard Russell Westbrook, a co-favorite alongside Harden for MVP honors, tallied 22 points, 11 rebounds, seven assists and nine turnovers. He missed 17 of 23 shot attempts and was largely rendered ineffective in the second half, scoring seven points as Houston extended its five-point halftime lead to 33 points.

The second half marked a complete offensive collapse for Oklahoma City, which scored 33 points on 28.9 percent shooting after the break. Westbrook had twice as many turnovers (four) as field goals (two) following the intermission, taking a seat for good at the 4:14 mark of the fourth quarter with Houston leading 110-80.

"That's my job, to get those guys easy shots," Westbrook said of his teammates. "I'll look at film and see what's open, where I can get those guys easy shots."

Beverley was blazing from the start, and his 3-for-4 first-quarter shooting helped carry the Rockets as Harden scuffled from the perimeter and the charity stripe.

While Harden labored through a 1-for-7 start, Beverley drained two 3-pointers. It wasn't until Harden started attacking the rim that he caught a rhythm, and his back-to-back driving layups cut the Thunder's lead to 29-27 entering the second quarter.

"None of that happens if the (opposing) team doesn't have their eyes on James," Beverley said. "He sees so many bodies every night and so many double teams. He's been phenomenal all year about making the right plays. He made the right play, it was just up to me to step up and make a shot."

Nene joined the fray in the second period, teaming with Beverley for a combined for 20 points and 12 rebounds in the first half. Beverley sandwiched a floater and consecutive 3-pointers around three Harden free throws in the third quarter to extend the lead to 73-62. Harden took over from there, scoring 13 points in the period as the Rockets hit four treys and 10 of 10 free throws.

"We had a hard time, I thought, scoring (in the second half)," Thunder coach Billy Donovan said. "We got a little bit bogged down here and there, but overall you've got to be able to make some shots, and we were unable to do that at a high enough level."

NOTES: Thunder F Andre Roberson made three 3-pointers in a game just three times in the regular season. He scored 18 points and finished 4 of 6 from behind the arc after 3-of-3 shooting in the first half. ... Oklahoma City led the league in offensive rebound rate at 27.9 percent but grabbed just four offensive boards in the first half and didn't record a second-chance basket until the 4:00 mark of the third quarter. The Rockets finished with a 31-4 advantage on second-chance points. ... The 31-point margin of victory was the third largest in Houston's postseason history.