NBA Cup quarterfinal winners and losers: Stephon Castle leads Spurs’ upset of Lakers, Thunder destroy Suns

The quarter-finals of the 2025 NBA Cup ended on Wednesday with half of the Western Conference table. As expected, the Oklahoma City Thunder made the Phoenix Suns’ job easier to improve to 24-1 this season and ties the best 25-game start in league history. Later, the San Antonio Spurs put up a brilliant offensive display to upset the Los Angeles Lakers.

In the Eastern Conference on Tuesday, the Orlando Magic came back from a 15-0 deficit to defeat their in-state rivals, the Miami Heat, while the New York Knicks used a dominant second quarter to overtake the Toronto Raptors and win for the eighth time in their last nine games.

The NBA Cup semi-finals are set for Saturday in Las Vegas:

• Knicks vs. Magic, 5:30 p.m. ET – Amazon Prime
• Spurs vs. Thunder, 9 p.m. ET – Amazon Prime

Before the Cup resumes, here’s a look at the winners and losers from the quarter-finals:

Loser: Anyone in the Thunder’s path

The Thunder are the defending champions and were 23-1 on Wednesday night, so there was no confusion about their status as the best team in the league. Still, their destruction of the Suns must have been demoralizing for the other 29 teams, and especially for those hoping to challenge for the title.

It was the first time the Thunder had anything on the line in a single game since Game 7 of the Finals, and if this is what it looks like when they step on the gas, good luck to everyone else. Sure, the Suns were shorthanded, but the gap between the Thunder and the next best teams seems bigger than ever.

The Thunder have now won a franchise-record 16 games in a row, and their 24-1 start is tied for the best in NBA history with the 2015-16 Golden State Warriors. Their 49-point victory on Wednesday was the largest margin of victory in the league this season and was already their fifth victory by more than 30 points (the single-season record is 10).

If you want more proof of their dominance, check out this stat, courtesy of Ben Golliver:

Winner: Stephon Castle

Stephon Castle was named near-unanimous Rookie of the Year last season, but was dismissed in some corners as simply the best in a series of bad options. But while his class may not be among the best, Castle has proven this season that he’s no charity case. His effort Wednesday night to lead Spurs into the semifinals was his latest proof.

Castle, who just returned from a hip flexor injury that kept him sidelined for more than three weeks, finished with a game-high 30 points, 10 rebounds and six assists on 10-of-14 shooting from the field, including 3-of-6 3-pointers. He was everywhere on both sides of the ball and joined Tim Duncan and Victor Wembanyama as the only Spurs players to have a 30/10/5 game at 21 or younger.

Wembanyama and second overall pick Dylan Harper rightfully receive as much attention, but Castle’s performance against the Lakers was a strong reminder that he’s also an important part of the Spurs’ future.

Loser: the Lakers defense

The Lakers entered Wednesday night’s quarterfinal with the 21st-ranked defense in the league (116.2 defensive rating). That figure will only get worse after their no-show against Spurs.

The Spurs scored 39 points in the first quarter and never looked back. They broke the 30-point mark in each of the first three quarters – they “only” managed 28 in the fourth – and scored 132 points for their highest-scoring fourth game of the season. San Antonio shot 50% from the field, made 17 3-pointers, got to the line for 36 free throws (they made 29) and only turned the ball over 10 times.

All night long, the Spurs could do whatever they wanted. There was little resistance from the Lakers’ perimeter players on their drives, and even less when they came out in transition. They scored 27 fast break points, including two late in the first half on a notable possession where Harrison Barnes got an uncontested dunk because the Lakers stopped playing for some reason.

The Lakers have an incredible offense, and as long as Luka Dončić, LeBron James, and Austin Reaves are all healthy, they will win a lot of games. But to ultimately compete for the Western Conference crown, they’ll need to find a way to stop. It’s worth noting that they are the only team in the bottom third of the league in terms of defensive rating with a winning record.

Winner: The Knicks

The Knicks have flown under the radar this season — partly because they got off to a mediocre start, but largely because there have been other, more interesting stories. Over the past few weeks, however, the Knicks have started to get back into shape.

The Knicks and Jalen Brunson call back to the East as they advance to the NBA Cup semifinals

Jack Maloney

They have won eight of their last nine games to improve to 17-7 and move within two games of the Detroit Pistons for first place in the Eastern Conference. Tuesday’s big win against the Raptors was a reminder of why they are currently the Eastern Conference favorites (+270, according to Caesars) despite being second in the standings.

The semifinals in Las Vegas will be an opportunity for the Knicks to take center stage for perhaps the first time this season and ensure they are no longer overlooked. And, while the NBA Cup is obviously nowhere near as important as the Finals, the competition offers a franchise lacking success an opportunity to lift a trophy.

The Magic traded Kentavious Caldwell-Pope, Cole Anthony, a 2025 first-round pick (Yang Hansen), three unprotected first-round picks (2026, 2028, 2030) and a trade of 2029 first-round picks (first two protected) to acquire Desmond Bane from the Memphis Grizzlies during the offseason.

It was a huge price to pay, especially for a non-superstar, and when Bane and the Magic got off to a rough start this season, Grizzlies fans were taking victory laps. It turned out that Bane just needed time to acclimate to a new city and his teammates.

Bane has been very good for a few weeks now, but it must have been good for him to have a big night in a showcase match in front of a national audience. There’s no better way to remind everyone that you’re a borderline All-Star than by scoring 37 points (14 of 24 from the field, including 6 of 9 from 3-point range) and grabbing six rebounds and five assists in a comeback victory.

During the Magic’s 8-3 stretch, Bane is averaging a team-high 22.2 points with shooting splits of 46/38.7/96, 4.6 rebounds and 4.6 assists.

Grayson Allen has had an incredible start to the season for the Suns, but has struggled since returning from a quad injury that kept him sidelined for just over two weeks. He did not return to action on Wednesday.

Not only did Allen finish with just 10 points on 3-of-9 shooting from the field in the Suns’ 49-point loss (the worst loss in team history), but he was also ejected in the third quarter after throwing Chet Holmgren to the floor.

The piece was revised and upgraded to a Flagrant 2, which, to be fair to Allen, seemed a bit harsh. Even so, it was a completely unnecessary moment that will only further tarnish Allen’s reputation.