LOS ANGELES — A classic, nationally televised duel between Stephen Curry and LeBron James was spoiled Saturday when three replay reviews and four shot clock malfunctions interrupted the fourth quarter of the Golden State Warriors’ 128-121 victory over the Los Angeles Lakers.

Here was a night where the NBA’s worst bureaucratic impulses completely and irrefutably ruined the latest showdown between its signature superstars. The sport’s beautiful, magnetic simplicity was lost in a convoluted stoppage of play that lasted nearly 20 minutes, an unnecessary series of pauses that tested the patience of the protagonists, Curry and James, as well as the 18,000-plus fans in sold-out Crypto.com Arena.

The Warriors and Lakers, who are locked in a tense battle for positioning in the Western Conference’s play-in tournament chase, appeared headed for a dramatic finish when James drilled a step-back three-pointer over Curry with 2:07 left to play. The shot, which came as James faded to his left, cut Golden State’s lead to 124-120.

Play continued the other way until the ball went out of bounds during a rebounding scramble on Golden State’s next possession. The referees were unable to determine which player last hit the ball, so they initiated a video review.

To the surprise of both teams, James’s three-pointer was retroactively taken away during the lengthy review. An official based in the NBA’s remote video center in Secaucus, N.J., determined James was out of bounds during his shot attempt because his left heel touched the sideline. That decision restored the Warriors’ lead to 124-117.

Adding further complication and delay: The referees made the rare determination that a Warriors player and a Lakers player had simultaneously deflected the ball out of bounds on the subsequent play, thereby requiring a jump ball to restart the action.

Once the jump ball was tossed, Warriors forward Draymond Green appeared to step on the baseline as he attempted to corral possession. The referees initially missed Green stepping out of bounds, forcing the Lakers to challenge the play so they would get possession. After another extended review, the referees deemed the Lakers’ challenge to be successful and awarded them the ball.

Unfortunately, the comedy of errors was just getting started. When the Lakers tried to inbound the ball, the game clock started but the shot clock did not. Noticing the problem, the referees stopped play and convened at the scorer’s table to address the issue.

No fix was forthcoming. Instead, the same scene repeated three more times: The Lakers inbounded the ball, the shot clock didn’t start properly, and the game had to be whistled dead.

Lakers public address announcer Lawrence Tanter finally informed the exasperated crowd he would verbally announce the shot clock over the sound system so play could continue.

All told, from the start of the first video review to the end of the final shot clock malfunction, it took 18 minutes 42 seconds to play 15 seconds of game action.

During the interminable stoppage, James slammed the ball to the court in frustration and then threw it to the ceiling in dismay. Curry showed off some flashy dribbling skills and wandered around shaking his head. Klay Thompson checked his wristband as if it were a watch, and players from both teams went through running exercises to stay warm. Meanwhile, the ABC broadcast cut to multiple commercial breaks and showed celebrities such as actor Ben Affleck and rapper Bad Bunny, who were unable to contain their boredom in their courtside seats.

“I’m too old for this s---,” James said, within earshot of the ABC television crew.

Rather than a tense endgame battle between James, who scored a game-high 40 points, and Curry, who finished with a team-high 31 points, the rest of the contest was an afterthought. The Warriors held on to their comfortable cushion, the last minute played out without any major developments, and both teams retreated to their respective locker rooms, where they tried to make sense of what had just happened.

“It was bizarre,” Warriors Coach Steve Kerr said. “It seems like a few times a year you get clock issues. That’s about as extreme as I’ve ever been a part of. It’s unfortunate. I felt bad for the fans. It was a great game, and all of a sudden, the last two minutes, everyone is looking at each other wondering what to do.”

James said he hadn’t previously had a basket taken away on a retroactive review and the call “took some momentum away” from the Lakers because it restored the Warriors’ seven-point lead. The four-time MVP added that he thought the review ruling was incorrect, because one replay angle appeared to show his left heel might not have made contact with the floor during his shooting motion.

“I didn’t believe I stepped on the line, obviously,” James said. “I knew how much space I had over there. When I shoot, I shoot on my tippy toes. It’s kind of hard for me to have a heel down.”

Though the Warriors were the beneficiaries of James’s erased three-pointer, Kerr said he doesn’t like the retroactive review process and would “love to see that rule go away.”

“I think we’re trying so hard to get everything just right at the expense of the [game’s] flow,” Kerr said. “Who cares if a guy’s foot is half an inch on the line? Is that worth going back 45 seconds and changing everything with the unintended consequences? ... I’m not a fan of replay. I think we should have replay just for the buzzer-beaters, and that’s it.”

Curry was befuddled by the machinations of the off-site review process, which involves the game officials huddling around a monitor and donning a headset at the scorer’s table so they can communicate directly with an off-site official in Secaucus.

“I’ve always wanted to know the conversation when they put the headphones on,” Curry said. “Who are they talking to and what’s the back and forth? ... [The three reviews] were all plays where you have to zoom all the way in and technology gets the best of you, when you’re always trying to get it down to the frame where you can see it definitively. It was weird those three plays were all in a row.”

As for the shot clock malfunctions, Curry and Thompson both said they wished the referees had decided more quickly to have Tanter announce the time.

“I don’t know why we had the hope we did after the second [attempt],” Curry said. “Every time we put the ball in and thought we were good, they take two dribbles and the whistles came back. I’ve never seen anything like that in my 15 years.”

By night’s end, Curry’s mesmerizing three-pointers and James’s valiant attempt to carry the Lakers without Anthony Davis, who left in the first half with an eye injury, were long forgotten. Thompson’s 26 points off the bench and Draymond Green’s near triple-double were overshadowed by an aggravating replay process that swallowed the game and a two-bit shot clock fiasco, which should be inexcusable in a technology-obsessed league that generated more than $10 billion in revenue last season.

The Warriors (35-31) barely even celebrated a crucial victory, which moved them a half-game above the Lakers (36-32) as the Pacific Division rivals continue to jockey for the West’s final two play-in spots. Like everyone else in the building, they just wanted to be freed from the excruciating purgatory.

“It was crazy,” Green said. “Do something. Finish the game already. That was nuts.”