SALT LAKE CITY – That dateline says it all, folks: As a result of two first-round upsets, it was Salt Lake City, not Houston or Dallas, where one of the two Western Conference semifinals began last night. The twin killings — Utah’s defeat of the Rockets, and the Golden State Warriors’ shocking upset of the Mavericks — turned the NBA playoffs upside-down this past week.

It wasn’t supposed to be this way. Dallas had rolled to a 67-win season that tied for the sixth-best regular-season mark of all time, while the Rockets had ripped off 52 victories despite losing both Yao Ming and Tracy McGrady for chunks of the season. The Texas rivals seemed headed for a secondround showdown that would pit the best player from Europe (likely MVP Dirk Nowitzki) and the best player from Asia (Yao), one that was greatly anticipated because the first-round pairings seemed so ho-hum.

Instead, the NBA playoffs threw us a rare curveball. This isn’t like the NCAA Tournament, where lower seeded teams routinely knock off their higher-seeded rivals. Golden State became the first no. 8 seed to beat a no. 1 since the NBA went to a best-of-seven firstround format, and only the third since the field expanded to 16 teams in 1984.

Meanwhile, Utah stunned the Rockets’ home crowd by stealing Game 7 on Saturday, 103–99 — becoming only the 19th team in league history to win Game 7 on the road. It was a particularly harsh setback for McGrady, who had said it was “on me” to get Houston out of the first round and couldn’t finish his post-game press conference because tears were welling up.

The Rockets guard is now 0-for-6 in first-round playoff series for his career, and he’s facing more questions than ever about his postseason mettle after taking just one shot in the final four and a half minutes of the rubber match.

The losses leave both Dallas and Houston reeling, and trying to figure out where they go from here. In each case, the questions start with the coaches and the star players.

For Dallas, Avery Johnson has been criticized for changing his lineup before the first game of the series to match up with the faster Warriors, with the argument being that as the no. 1 seed he should have made Golden State be the ones to adjust. This is perhaps too simplistic — the Warriors were too fast for Dallas no matter who Johnson played. But it is true that his starter in that game, Devean George, proved to be worthless over the course of the series, and that Dallas in general seemed to lean far to heavily on its veteran role players.

But the real heat has been aimed at Nowitzki, who didn’t look much like an MVP while enduring a 2-for-13 nightmare in the closeout game. The 7-footer was flustered all series by the Warriors’ double teams and their use of smaller, quicker defenders to pester him while he made his moves. In the wake of his flop, fans immediately demanded a recount of the MVP vote.

It’s the second straight postseason disappointment for Dallas, who dropped its final four games of the Finals a year earlier against Miami. The Mavs are now 2–8 in their past 10 playoff games, and some are wondering if the team lacks the requisite toughness to compete in the postseason.

In this case, I think the solution is a little simpler. Dallas ran into a buzzsaw — the Warriors have been on fire since Baron Davis returned from injury in early March — and it didn’t help that Golden Sate’s coach, Don Nelson, used to coach the Mavs and intimately knew their strengths and weaknesses.

Thus, Dallas needs to be careful not to overreact, as this wasn’t your typical no. 1 vs. no. 8 series. Rather than making a panic trade of Nowitzki or fellow All-Star Josh Howard, Dallas should focus on making moves around the edges to sharpen themselves for next year’s playoff battles. They need to get more shooters to burn the doubleteams opponents send at Nowitzki, and should consider trading Jason Terry for a true shooting guard, which would open a spot for waterbug Devin Harris to run the point full-time.

Meanwhile, Houston’s situation is also in flux. Rumors abounded the day after the defeat that coach Jeff Van Gundy will resign, with no definitive word yet to come out of Houston as to his plans. The former Knicks boss has only one nonguaranteed year left on his contract and has yet to lead Houston out of the first round in his four seasons at the helm.

But the Rockets’ problems won’t be solved by a coaching change, as they have to figure out how to get their stars some help. As with Nowitzki, the spitballs the press is lobbing at McGrady this week are a bit unfair. His career playoff numbers are some of the best in history, and even in defeat in Game 7 he either assisted or score on 25 of the Rockets’ 34 baskets.

Houston’s problem is that their two superstars are surrounded by some very modest talents. The Rockets only had one productive bench scorer in guard Luther Head, and otherwise relied on defense-minded role players like Shane Battier, Chuck Hayes and Dikembe Mutombo.

This lack of support was most apparent in the Game 3 defeat, in which Houston mustered only 67 points and just four players scored. Point guard and power forward will be the areas of focus, as the Rockets’ inability to get scoring from those two spots allowed the Jazz to tighten the noose around Yao and McGrady.

But as with Dallas, there’s a danger in letting what happened in six games in April override what happened in the previous 82. Dallas and Houston were considered fearsome opponents when the playoffs began; the reason the outcome was so disappointing was precisely because their hopes were so high.

For each team, the playoff result indicated that more work needs to be done. But neither club should contemplate reaching for the dynamite. Fortunately, they have two months to let cooler heads prevail before the off-season wheeling and dealing begins.

In that time, they may come to appreciate how good they were from November to April, and how comparatively smaller modifications are needed to continue their seasons into May and June. As disappointing as the postseason was for both teams, there’s every reason to believe I’ll have a dateline from one of those two places a year from now.

jhollinger@nysun.com