The Los Angeles Lakers walked out of Ball Arena with a 112-106 win over the Denver Nuggets late Saturday night, handing the West’s top seed an unexpected Game 1 loss and rearranging the early storyline of an NBA postseason that completed its opening round of games on Sunday with four more series getting underway. By Monday morning, half of the league’s eight first-round matchups arrived at a 1-1 split, three favorites had held serve, and the Lakers stood alone among the lower seeds with a road win in hand.

Game 2s in four series begin Monday night, with Boston hosting Detroit at 7 p.m. Eastern, Cleveland hosting Miami at 7:30, the New York Knicks hosting the Indiana Pacers at 8, and the Nuggets-Lakers series resuming in Denver at 10. The remaining four Game 2s, drawn from Sunday’s openers, will play Tuesday and Wednesday.

The Lakers’ win, sealed by an 11-2 closing run over the game’s final three minutes, was paced by 34 points from LeBron James and a 22-point, 14-assist outing from rookie guard Kasparas Jakucionis, whose late drive-and-kick to forward Rui Hachimura produced the dagger three-pointer with 41 seconds left. Denver’s Nikola Jokic recorded a triple-double — 29 points, 13 rebounds and 12 assists — but committed seven turnovers, four of them in the fourth quarter.

“We did not come into this building expecting a coronation, and we are not leaving it under any illusion that we have won anything,” Lakers head coach JJ Redick said in his postgame availability shortly after midnight Mountain time. “What we have is a road win and a film session. Both are useful. Neither is the series.”

Denver head coach Michael Malone, asked about Jokic’s late turnovers, declined to single out his center. “We had seven possessions in the last three minutes to put the game away or tie it, and we got two shots up,” Malone said. “That’s a group failure, not a one-man failure. We’ll fix it Monday.”

Boston, the East’s No. 1 seed, opened the postseason Saturday afternoon with a 118-99 win over the Detroit Pistons that Pistons guard Cade Cunningham, who finished with 18 points on 6-of-19 shooting, called “as flat a game as we have played in two months.” Celtics forward Jayson Tatum scored 31 points and added eight rebounds; reserve guard Payton Pritchard added 17 off the bench, including five three-pointers in the third quarter when Boston broke a one-point game open with a 22-4 run.

In Cleveland, the No. 2 Cavaliers held off the Miami Heat 104-99 behind 33 points from Donovan Mitchell and 24 from Evan Mobley. The Heat were paced by Tyler Herro’s 28 points; forward Jimmy Butler, who had been listed as questionable with a right knee contusion, played 31 minutes and finished with 14 points and nine rebounds. Heat head coach Erik Spoelstra called the loss “the closest five-point game I can remember coaching,” and said his rotation would not change for Monday’s Game 2.

The Pacers handed the Knicks the first home upset of the weekend, winning 109-103 at Madison Square Garden behind 32 points and 11 assists from guard Tyrese Haliburton. Knicks guard Jalen Brunson, cleared to play earlier in the week after a left wrist scare, scored 24 points on 7-of-22 shooting and turned the ball over six times. New York’s Karl-Anthony Towns went 4 of 14 from the floor. The series shifts back to Indianapolis for Game 3 on Thursday after Monday’s New York-hosted rematch.

Sunday’s Western Conference openers produced fewer surprises. Oklahoma City, the West’s No. 2 seed after Denver inherited the top line in the regular season’s final week, dispatched the Sacramento Kings 121-101 behind 38 points from Shai Gilgeous-Alexander, who was named the league’s scoring champion earlier in the day. The Orlando Magic, seeded fourth in the East, beat the visiting Milwaukee Bucks 106-99; Bucks forward Giannis Antetokounmpo, who had missed three of the regular season’s final five games with a strained left calf, played 34 minutes and finished with 27 points and 13 rebounds. He told reporters afterward the calf was “where it needs to be.”

The night’s marquee West game went to Houston, where the No. 3 Rockets beat the Minnesota Timberwolves 110-104 behind 29 points from guard Jalen Green, whose 39-point performance in the play-in tournament had been the talk of last week’s bracket-setting weekend. The late game, between the Warriors and Phoenix Suns at Chase Center, finished after most East Coast deadlines: Golden State 122, Phoenix 117 in overtime, with Stephen Curry scoring 39 points and forward Jimmy Butler adding 25 points and 10 rebounds.

The opening weekend’s two upsets — the Lakers in Denver and the Pacers in New York — drew the largest postseason television windows in three years, according to early figures the league shared with broadcasters Sunday night. The Saturday late game between the Lakers and Nuggets, which aired on ESPN, averaged 5.4 million viewers, the network said in a release Monday morning; the audience peaked above 7 million during the final two minutes.

“You expect the league office to push these matchups, and you expect viewers to find them, but the size of the bump for Lakers-Nuggets was at the higher end of what anyone had projected,” said Karen Maldonado, a sports-media analyst at MoffettNathanson. “James in what he says is his final season, Jokic chasing a fourth MVP, a road upset late at night on a Saturday — that’s a window the league does not always get.”

Elsewhere in the day’s sports calendar, Major League Baseball entered its fourth week with the Detroit Tigers and Baltimore Orioles still atop the American League at 13-4 and 12-5 respectively after the two teams split a four-game weekend series at Comerica Park. The New York Yankees, after dropping two of three to the Houston Astros, fell to 6-11 on the season and announced Sunday night that pitching coach Matt Blake had been reassigned. Manager Aaron Boone, addressing reporters in the Bronx before Monday’s home opener against the Tampa Bay Rays, said the move had been “in conversation for a couple of days” and that the club expected “to play a brand of baseball that looks like the Yankees inside of two weeks.”

The NBA’s first round is scheduled to continue through the weekend, with Game 5 of any series still alive set to be played April 28 and 29. The league office said the conference semifinal pairings and broadcast schedule would be finalized within 24 hours of the last first-round series ending.