The Western Conference Semifinals series between the No. 2 San Antonio Spurs and No. 3 Houston Rockets was widely considered the best matchup of the NBA playoffs’ second round, and for good reason. The tilt between the in-state rivals featured most everything a fan could want from the postseason — two of the four best teams in the league, two bona fide MVP candidates in Kawhi Leonard and James Harden, head coaches with differing styles and past playoff meetings, and four tightly contested regular season games to serve as proof of concept. Monday night’s Game 1 at the AT&T Center would pit all these factors against each other to begin an epic tilt.

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It took Houston just a few minutes to establish themselves as new favorites in a series that had previously looked something close to a toss-up. Gregg Popovich called his first timeout after just 80 seconds, and the Rockets scored 15 points in the first 4:05 of the first quarter on their way to an 11-point lead after one. That margin nearly tripled in the next period as the visitors dominated the Spurs in every facet of the game. Houston got everything they wanted to lead 69-39 at the break, good enough for the largest halftime deficit in San Antonio’s lengthy playoff history. Houston maintained control in a garbage time-laden second half to build the margin to as many as 39 points, and Game 1 ended with a 126-99 blowout win that has upended many assumptions regarding this series. The worst home playoff loss in a successful franchise’s history tends to force a reassessment.

It’s difficult to identify any kind of cause-and-effect for the extent of the blowout, because the Rockets looked comfortable immediately. James Harden orchestrated the offense at an expert level, finding his team’s bevy of three-point shooters regularly and hitting center Clint Capela for lobs and open looks at the hoop seemingly just as often. The Rockets made 12 three-pointers and were able to play at Mike D’Antoni’s preferred pace with a paucity of mid-range looks — in terms of process, it was the perfect first half.

Perhaps most impressively, the Rockets didn’t even have to shoot especially well to control the game. While they certainly started hot — 15 points in just over four minutes is a heck of a foundation to work from — the Rockets finished the first half having made fewer than half their field goals (23-of-47), saw no player make more than half his three-point attempts, and got no points from Sixth Man of the Year candidate Eric Gordon. Rather, they succeeded because they controlled the terms of the game. Houston took a whopping 27 three-pointers in the half and made the league-best San Antonio look incapable of stopping anything. It wasn’t as if the Rockets beat the Spurs with good shooting that will be difficult to reproduce — they just dominated every matchup on the court.

Meanwhile, the Spurs appeared to live out a worse-case scenario. Most pre-game analysis identified a few potential problem areas for the Spurs — the inability of their big men to guard James Harden on his forays to the hoop, the lagging production of backcourt starters Tony Parker and Danny Green, and the offense’s overreliance on Kawhi Leonard.

All proved difficult to solve. Starting forward David Lee was immediately targeted defensively and looked out of his depth throughout the game, and LaMarcus Aldridge didn’t fare much better on his way to an absurd minus-36 in 25 minutes. Green was subbed out for the first time after only a few minutes and combined with Parker to shoot a mere 1-of-11 in the first half. Leonard started OK with 12 points on 4-of-9 shooting but began to force plays as things got out of hand and finished with a team-high 21 on 5-of-14 from the field. Playoff series are largely about adjustments, and it’s likely that the Spurs will try new lineups and find better luck in Game 2 and beyond. Nevertheless, the Rockets pinpointed their weaknesses and exposed them mercilessly. San Antonio couldn’t defend, couldn’t score at anything approaching a competitive rate, and now has to consider if certain players deserve to see serious minutes over the rest of the series.

It’s not clear Popovich has many good options. The Spurs have been on the other side of games like this one before and gone on to lose the series — check out Game 1 of last spring’s Western Conference Semifinals for a recent reminder — but those opponents have typically had star depth to create the necessary improvement.

Simply put, this Spurs roster looks like Kawhi and a bunch of aging role players. Aldridge in particular looks like a shell of his former All-Star self, to the point where it’s difficult to remember why so many teams lined up to offer him max contracts just two summers ago. Parker performed well in the first round against the Memphis Grizzlies but faces a whole different challenge against a deep Rockets backcourt that likes to push the pace. Pau Gasol shouldn’t be playing more than 20 minutes per game, Danny Green has now scored in double figures once in seven playoff games, and David Lee was considered a roster-filler before the Spurs somehow turned him into a positive contributor this season. Manu Ginobili put up eight points on 3-of-7 shooting in this game, and that was his second best game of the postseason to date.

Popovich can try to give more minutes to athletic reserves like Jonathan Simmons and Dewayne Dedmon, but those guys barely played against the Grizzlies and are last resorts for a reason. Crazier ideas have worked before, but does an ostensible contender really want to rely on such players one game into the conference semis? The league’s best teams are not supposed to go this deep into the bench so soon.

Again, the best news for the Rockets in this series is that they can repeat these shooting percentages again. Their 22 three-pointers set a new franchise playoff record, but the process that got them 50 attempts is what stood out in this commanding victory. For that matter, Harden’s 20 points and 14 assists showcased a superstar in full command of his abilities. He was good enough that Popovich may have to consider putting Leonard on him full-time, a decision that could cause even more problems for the Spurs’ lagging offense.

To be sure, the Rockets are not going to sweep the Spurs with four-straight 30-point blowouts. This game could have been different if Houston hadn’t set the tone early, or even if secondary players like Trevor Ariza (23 points on 5-of-10 3FG) and Capela (20 points on 8-of-10 FG and 13 rebounds) hadn’t offered such consistent threats. San Antonio will surely gain better control of the pace of play and figure out a way to push Houston out of its preferred areas. They’re too good to lose this badly more than one time.

However, there’s a difference between competing and finding a way to win the series. The Rockets set the terms of this series in convincing fashion on Monday. It’s now up to the Spurs to upend them.

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Eric Freeman is a writer for Ball Don’t Lie on Yahoo Sports. Have a tip? Email him at efreeman_ysports@yahoo.com or follow him on Twitter!

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