The SportsNation panel discusses how important the No. 1 seed is for the Celtics and if they can get past the Cavaliers. (1:28)

BOSTON -- The Celtics have secured the No. 1 seed in the Eastern Conference playoffs.

Boston overcame a sluggish start to top the Milwaukee Bucks 112-94 on Wednesday night at TD Garden. With a record of 53-29, the Celtics finished two games ahead of a Cleveland Cavaliers team that prioritized rest in the final days of the regular season.

Even before the Celtics finished off a dominant fourth quarter against the Bucks, the Cavaliers lost to the Toronto Raptors 98-83 to ensure Boston's top spot.

The Celtics will host the eighth-seeded Chicago Bulls in the opening round of the playoffs, beginning Sunday (6:30 p.m. ET, TNT). The teams split their regular-season series 2-2.

"They're the eighth seed, but they're better than what seed they are," Celtics guard Isaiah Thomas said after Wednesday's win. "They're a really good team, especially with Dwyane Wade back [from a broken elbow]. So we have to be ready for them."

Added Celtics teammate Al Horford: "They've been playing much better. I think that they have a lot of experience, obviously with Dwyane Wade, [Rajon] Rondo, [Jimmy] Butler, the list goes on. They have just a lot of guys that have been in playoff atmospheres, are familiar with them. They've been playing much better. It should be a fun series."

Isaiah Thomas and the Celtics split four regular-season games against the Bulls. The teams open their first-round playoff series Sunday in Boston. Winslow Townson/USA TODAY Sports

The Bulls topped the Brooklyn Nets 112-73 on Wednesday night to secure their postseason berth.

The Indiana Pacers emerged with the seventh seed after a 104-86 triumph over the Atlanta Hawks. The Pacers will play the second-seeded Cavaliers in the opening round, beginning Saturday (3 p.m. ET, ABC).

"I feel very confident that we've got a good run in us,'' Cleveland coach Tyronn Lue said. "I think we're good.''

The Miami Heat, who defeated the Washington Wizards 110-102 on Wednesday, were squeezed out of the postseason based on a tiebreaker with the Bulls. Miami was 11-30 in the first half of the season, then 30-11 in the second. According to the Elias Sports Bureau, prior to the Heat's finish this season, the best record over its final 41 games by any team that missed the playoffs was the 1970-71 Phoenix Suns, who finished 26-15.

The rest of the East teams were already locked into their playoff positions before Wednesday: Toronto at No. 3, Washington at No. 4, Atlanta at No. 5 and Milwaukee at No. 6. The Raptors host the Bucks to begin their first-round series Saturday (5:30 p.m. ET, ESPN), while the Hawks will open a series at the Wizards, beginning Sunday (1 p.m. ET, TNT).

In the West, the eight playoff teams were set entering Wednesday night with only the final seeding for the 4-5 teams at stake. The LA Clippers settled that with a 115-95 victory over the Sacramento Kings that nailed down the No. 4 seed and pushed the Utah Jazz to No. 5. The two teams open their playoff series Saturday at Los Angeles, with tipoff set for 10:30 p.m. ET on ESPN.

The other West playoff matchups are top-seeded Golden State vs. No. 8 Portland, beginning Sunday (3:30 p.m. ET, ABC); No. 2 San Antonio vs. No. 7 Memphis, beginning Saturday (8 p.m. ET, ESPN); and No. 3 Houston vs. No. 6 Oklahoma City, beginning Sunday (9 p.m. ET, TNT).

Celtics vs. Bulls in Round 1 A look at the first-round series between the top-seeded Celtics and the No. 8 Bulls: • Teams split season series 2-2

• Celtics: 73 percent chance to win series, according to ESPN Basketball Power Index

• Fifth all-time meeting in postseason (Celtics won previous 4)

• Last meeting: 2009 first round (Celtics won in 7 games; 4 of the games went to OT, including a double- and triple-OT game)

• Celtics: Seventh 1-seed in franchise history (reached NBA Finals five of previous six times; won 3 titles)

• Celtics: 1-seed for first time since 2007-08 (won NBA title)

• Bulls: 3-14 all time vs. Celtics in playoffs (all 3 wins in OT in 2009 first round)

• Bulls: Record vs. Celtics in postseason is worst against any opponent

-- ESPN Stats & Information

Almost as if paying tribute to a season in which very little has come easy, the Celtics dug themselves a 13-point first-half deficit Wednesday night and, even after rallying to go ahead, fell behind again early in the fourth quarter. Boston finally motored away from the Bucks with a late-game burst.

The Celtics were playing only their 36th game with their preferred starting lineup of Thomas, Horford, Avery Bradley, Jae Crowder and Amir Johnson. The Celtics, who appear healthy heading to the postseason, are 26-10 (.722) this season when they play that starting five.

Thomas started slowly Wednesday but sparked a late second-quarter rally that helped Boston take a one-point lead into halftime. Still, the Celtics trailed early in the fourth quarter before an absolutely dominating run to close out the game.

"It's very special," Thomas said of the top seed. "I've never been a No. 1 seed, so it's something that I'm excited about, but once you get in the playoffs, the seedings kind of go out the window. You just have to take care of business and be locked in from the jump."

Added Celtics coach Brad Stevens: "Played [the Bulls] four times, split it. Really physical team. Great offensive rebounding team, with multiple proven playoff players. Played good basketball in the games I've watched recently, and so we're going to have our hands full. But I guess it's the playoffs; that's what's supposed to be the case. We're looking forward to competing."