SAN ANTONIO, TEXAS - DECEMBER 23: Shai Gilgeous-Alexander #2 of the Oklahoma City Thunder is fouled on a layup attempt by Victor Wembanyama #1 of the San Antonio Spurs during the game at Frost Bank Center on December 23, 2025 in San Antonio, Texas. (Photo by Kenneth Richmond/Getty Images)Getty ImagesThroughout its 80-year history, the NBA has been built on rivalries.Bill Russell vs. Wilt Chamberlain. Larry Bird vs. Magic Johnson. Michael Jordan vs. Isiah Thomas and the Bad Boy Pistons. LeBron James vs. Stephen Curry.The NBA is about to add the next chapter to that book.On Monday, the Oklahoma City Thunder and San Antonio Spurs will meet for Game 1 of the Western Conference Finals. The Thunder are the reigning champions and are led by soon-to-be two-time MVP Shai Gilgeous-Alexander. The up-and-coming Victor Wembanyama-led Spurs look like their biggest roadblock to multiple championships in the coming years.The Thunder and Spurs met five times during the 2025-26 regular season, including in the semifinals of the vaunted NBA Cup. The Spurs won the first three of those meetings and the final one, while the Thunder's lone win over the Spurs came in mid-January.Even more terrifying for the Thunder: Wembanyama came off the bench in each of those first three Spurs wins.Regular-season success doesn't always translate to the playoffs, though. Just ask the Toronto Raptors about how well they fared against the LeBron James-led Cleveland Cavaliers in the late 2010s. But thanks to Wembanyama and their star-studded backcourt, the Spurs do pose unique challenges to the Thunder in their quest to repeat.That could make for an epic Western Conference Finals—and a launching pad for the NBA's next great rivalry to unfold.MORE FOR YOUThe Playoffs Breed HostilityThe best rivalries in NBA history didn't start in the regular season. They stemmed from multiple meetings in the playoffs.Russell and Chamberlain clashed in the playoffs eight times throughout their Hall of Fame careers, with Russell winning seven of those series. Bird and Magic met three times in the NBA Finals, with Bird's Boston Celtics winning in 1984 and Magic's Los Angeles Lakers winning in 1985 and 1987. The Bad Boy Pistons beat Jordan's Chicago Bulls in three straight years—and won championships in 1989 and 1990—before Jordan's Bulls swept them in the 1991 Eastern Conference Finals en route to their first of six championships. LeBron and Curry clashed in four straight NBA Finals, with Curry's Golden State Warriors winning in 2015, 2017 and 2018 and James' Cleveland Cavaliers overcoming a 3-1 series deficit in 2016. The Spurs and Thunder did meet three times in the playoffs over the five-year span between 2012 and 2016, but both rosters have completely turned over by now. Those Thunder squads were led by Kevin Durant and Russell Westbrook, while those Spurs teams had Tim Duncan and Kawhi Leonard.Battling for a trip to the NBA Finals—particularly if the Spurs stop the Thunder's quest to become the first repeat champions since Curry's Warriors in 2017 and 2018—will be rocket fuel for this budding rivalry.Granted, Wembanyama already spent the season watering those seeds.After the Spurs' Christmas Day win over the Thunder, Wembanyama told reporters that he was "glad to be part of something that's growing to be so beautiful—pure and ethical basketball." Many interpreted that as a direct shot at Gilgeous-Alexander, whose penchant for drawing free throws has earned him the "foul merchant" nickname from plenty of other fanbases.Wembanyama has also been clashing with Thunder big man Chet Holmgren in international tournaments long before they joined the NBA. He refuses to acknowledge that there's a rivalry between the two, though.With that said, Marc J. Spears of ESPN's Andscape suggested that Holmgren's championship last year added extra fuel to Wembanyama's fire."They've been going back to under 20s, under 18 even, right?" Spears said. "And Chet got a championship. Wemby doesn't have a championship. So I was told by somebody inside that room that Wemby is motivated by Chet. Chet having one up on him in the championship."The Western Conference Finals will be Wembanyama's chance to rectify that.Two Deserving Teams, Only One WinnerWith all due respect to the New York Knicks, who've barnstormed their way to the Eastern Conference Finals, the two best teams in the NBA this year might both be in the West.The Thunder finished with the league's best record at 64-18 even though star forward Jalen Williams played only 33 games during the regular season. They got off to a 24-1 start, tying the 2015-16 Warriors for the best 25-game start in NBA history, before losing four of their next six games. (Three of those losses were against the Spurs.) Although the Thunder didn't threaten the 73-win Warriors for the best regular-season record in NBA history, they did finish with the eighth-highest margin of victory of all time. Six of the seven teams ahead of them won the title that year. The lone exception, the 1971-72 Milwaukee Bucks, ran into another all-time great Lakers team in the Western Conference Semifinals that year.The Thunder's dominance was not limited to the regular season. Williams has played only 52 total minutes in the playoffs thus far due to a hamstring strain, but that didn't stop the Thunder from sweeping both the Phoenix Suns in the first round and the Lakers in the conference semifinals. They're only the fourth defending champion in NBA history to begin the playoffs 8-0, according to ESPN Research, and their margin of victory (16.6 points) is the fifth-largest heading into the conference finals since 1983-84.The playoffs have been more of a slog for the Spurs, who needed five games to dispatch the Portland Trail Blazers in the first round and six games to beat the Minnesota Timberwolves in the conference semifinals. The Spurs did go 62-20 during the regular season, though, and they finished with the league's second-best net rating, trailing only the Thunder.No matter what happens in this series, both the Spurs and Thunder are set up for sustainable success, which is increasingly rare to say in the NBA's second-apron era. This might be their first meeting in the playoffs with their respective cores, but it likely won't be the last. That’s the foundation of an all-time rivalry. Get your popcorn ready for Monday.Unless otherwise noted, all stats via NBA.com, PBPStats, Cleaning the Glass or Basketball Reference. All salary information via Spotrac and salary-cap information via RealGM. All odds via FanDuel Sportsbook.Follow Bryan on Bluesky.