The champs will live to fight another day, as the Spurs defeated the Hornets in Monday’s Game 7 to advance to the Western Conference Finals against the Lakers. Game 1 is tonight in Los Angeles.

But as they head into a best-of-seven series against the Lakers as heavy underdogs, one wonders if they merely prolonged the inevitable changing of the guard in the Western Conference by two weeks.

For the past half-decade, three teams — San Antonio, Phoenix, and Dallas — have dominated the West. Those teams have accounted for four of the five conference titles and seven of the 10 conference finals appearances in that time.

But their days atop the West may be numbered. Dallas and Phoenix already seem vulnerable, with each coming off a first-round exit that resulted in a coaching change and each sporting a roster that’s getting awfully long in the tooth.

That leaves San Antonio, the most successful of the trio, as the last one standing. While San Antonio has the same age issues as its two rivals, and like the others saw a modest decline in its regular season performance this season, they have a couple advantages in this fight.

For starters, they have the most cohesion. Dallas and Phoenix got sick of their coaches; it’s hard to imagine such a thing happening in San Antonio. Indeed, Gregg Popovich got as much out of his troops as ever in the New Orleans series, masterfully changing defenses in the seventh game to help put the squeeze on the Hornets’ Chris Paul.

They also have the best salary situation. In the NBA, the cap is king, and the Spurs have managed theirs superbly. Most successful teams inevitably get in a situation where they either must pay their stars and go over the luxury tax threshold or shed talent to avoid it; either way, it stops them from bringing in new blood, too. Both Dallas and Phoenix have been victims.

So far, the Spurs have avoided that fate, and their solid cap position may allow them to restock their alarmingly gray roster with great speed. San Antonio has few killer contracts and, with the exception of the deals for stars Tim Duncan, Manu Ginobili, and Tony Parker, no long-term ones.

Of course, cap flexibility isn’t going to help them much against the Lakers, and that’s the other half of this problem. L.A., New Orleans, and Utah are the rising triumvirate out West. It was they, and not Dallas, Phoenix, or San Antonio, who were the West’s three division winners this season, and it was they who had the conference’s top three average scoring margins — the best indicator of quality out there.

While Duncan and Ginobili are on the wrong side of 30 and even Parker (26) isn’t the kid he used to be, the Hornets and Jazz in particular seem built for the future. New Orleans’s All-Star duo of MVP runner-up Chris Paul (23) and power forward David West (27) seems set to dominate for half a decade or more; the fact that they’re also fast friends with fantastic chemistry only makes their future brighter. Throw in defensive ace Tyson Chandler (25) and they have a powerful nucleus.

Similarly, Utah has a star point guard of its own in Deron Williams, another pup at 23. Joining him up front is All-Star power forward Carlos Boozer (26), and two lesser-known rising studs, shooting guard Ronnie Brewer (23) and power forward Paul Millsap (23) add to their promise.

But the biggest threat of all out West is the Lakers, and that’s why the Spurs’ reign in the West may come to an end in the next fortnight. Since executing the midseason theft of Pau Gasol from Memphis, L.A. is simply the most talented team in the league.

For starters, obviously, they have the MVP in Kobe Bryant, a two-way stud who can take over late in games but this season has discovered the joys of getting his teammates involved early. Gasol, meanwhile, is a multitalented threat who can score on the blocks, take his man away from the hoop, run the floor, and find the open man. Next to them, Lamar Odom has settled in as a glue guy par excellence who punishes slower big men off the dribble.

The really scary part is how much quality young talent surrounds them. Center Andrew Bynum (20) looked like a budding All-Star before a knee injury set him back; he’ll undergo surgery and try again next year. Shooting guard Sasha Vujacic (24) and point guard Jordan Farmar (21) both had breakout years off the bench, power forward Ronny Turiaf (25) is a high-octane energizer, and sidelined wing Trevor Ariza (22) seems poised to break out next year.

All of which means we could be seeing the veteran Spurs’ last stand as the Western kingpin. They do match up well against L.A., with forward Bruce Bowen the league’s most noted Kobe stopper and Duncan a perfect foil for Gasol in the middle. And of course, their experience as four-time champions will help.

However, this is the first time in the past half-decade they’ve taken the floor for a playoff series as a heavy underdog, and with good reason. The Lakers are 30-6 since acquiring Gasol and show no signs of slowing down, regardless of the opponent. Look for them to topple the Spurs, perhaps in as few as five games, perhaps in as many as seven, but in a way that leaves no doubt that the times in the West are a-changing.

***

Well, the Knicks and Nets didn’t get lucky. New York will pick sixth and New Jersey 10th after yesterday’s NBA draft lottery provided no surprises for the locals. At those positions it’s anyone’s guess who the teams will pick, or if they’ll use the picks at all — most scouts regard it as a top-heavy year with two stud players in Memphis point guard Derrick Rose and Kansas State power forward Michael Beasley, but little depth.

But that open Chicago Bulls job just got a lot more interesting, huh? New Knicks coach Mike D’Antoni has to be kicking himself after the Bulls snared the top pick. Only two weeks earlier, D’Antoni chose the Knicks over Chicago.

With a solid nucleus of young talent already that includes forwad Luol Deng and Tyrus Thomas, center Joakim Noah, and guards Ben Gordon and Kirk Hinrich, the addition of a talent like Rose or Beasley could propel the Bulls back near the top of the East very quickly.

Meanwhile, the Bulls’ ascent actually knocked New York down a peg — if it all had gone according to form, the Knicks would have selected fifth.

jhollinger@nysun.com