OKLAHOMA CITY -- Entering the playoffs, the Oklahoma City Thunder were the youngest team in NBA history to secure a No. 1 seed since seeding began in 1984.

After missing the playoffs the past three seasons and working on a rebuild, the Thunder's reward as the top seed in the strong Western Conference was facing the 49-win New Orleans Pelicans, who had to fight through the play-in tournament but also boasted a league-best record on the road.

Seven of the 11 Thunder players who took the floor Sunday night were playing in their first playoff game. The relative inexperience showed itself at times in the fourth quarter, but the team also came through when it most needed to.

Shai Gilgeous-Alexander put the Thunder up on a three-point play with 32.5 seconds remaining in regulation, while rookies Chet Holmgren and Cason Wallace came up with big defensive plays to help Oklahoma City secure a 94-92 win in Game 1 of the first-round playoff series.

"Everybody that came in played their role," Gilgeous-Alexander said. "They gave good minutes. All 11 guys did their part, and that's the reason why we won tonight."

After Gilgeous-Alexander tied the score at 90 with 1:36 to go, the Pelicans' ensuing possession featured four shot attempts and three offensive rebounds -- but no points thanks to one final stop by Holmgren.

Pelicans center Larry Nance Jr. rolled to the rim and tried to get a shot over the outstretched arms of Holmgren, but the rookie met the ball at its apex to record his fifth block of the night.

"I was just trying to make a play," Holmgren said. "I didn't want to leave things in the hands of the other team, so I was trying to go up and make a play, whether I was going to be late and it was going to be a goaltend or not."

It was on the next possession that Gilgeous-Alexander gave the Thunder the lead for good.

The Pelicans answered with a quick basket on their next possession, and Holmgren then hit one of two free throws to make it a two-point game.

With 14 seconds left, the Pelicans got the ball to CJ McCollum, and Wallace was switched on to him. McCollum lost the ball at first but was able to get it back; he then stepped through Wallace's block attempt and let a shot go that looked on line but hit the back of the rim.

"I thought it was cash, and I missed it long," McCollum said. "But the game shouldn't have come down to that."

Both teams struggled to get going offensively early on. The game was tied at 17 after the first quarter and at 43 at halftime.

It was still the most hotly contested game of the NBA playoff weekend. There were 20 lead changes as compared to 19 lead changes in the other seven games combined.

New Orleans took a 90-88 lead -- the 19th of the game -- with 3:34 to go on a layup by Brandon Ingram but didn't score again until there were 26.5 seconds remaining. The Pelicans went 1-of-7 in the final 3:09 with four turnovers.

Oklahoma City held New Orleans to 38.5% shooting, and the Pelicans went just 1-of-15 on corner 3-pointers.

It was an impressive start for the No. 1 seed, but Thunder coach Mark Daigneault knows it's just the beginning.

"I just told the team, and I think it's true, these series are long," Daigneault said. "You have to improve through the series, and that's our challenge now. We got to watch the film, learn from it and be a better team on Wednesday than we were tonight."