The race for the Supporters' Shield came down to the final regular-season games, with the New York Red Bulls claiming the award for most points this season with a 1-0 victory over Orlando City on Sunday.
The playoffs were also set by the end of Decision Day, the final day of Major League Soccer's regular season when all of the league's games are played at the same time.
The Red Bulls' 71 points season eclipsed Toronto's MLS record of 69 set last season. The team also set the record (post-shootout era) with 22 total wins.
"The team has put a lot of effort in, but we've still got a lot of work to do," said forward Bradley Wright-Phillips, already looking ahead to the postseason.
Atlanta United had a one-point edge on the Red Bulls for the Shield going into the day, but fell 4-1 on the road to Toronto FC.
"When you have the opportunity to deny a trophy, deny the record, there's some motivation there because we have pride as a team," Toronto coach Greg Vanney said. Toronto didn't make the playoffs after winning the Supporters' Shield and the MLC Cup last season.
Atlanta coach Tata Martino said the loss was disheartening.
"This was the most important game of the year and obviously we didn't play well enough and we let all the hard work that we had done until that point got to waste. I didn't see a team that looked like it could turn the game," he said. "In the second half it looked like we had some moments but it seems like the team has lost the football that we had up until this point. So that is what we need to regain going into the playoffs."
As the top two teams in the Eastern Conference, the Red Bulls and Atlanta earned first-round byes for the playoffs. Sporting Kansas City and the Seattle Sounders clinched the first-round byes in the Western Conference.
When the day started there were two playoff spots up for grabs, one in the East and one in the West.
Out West, Real Salt Lake was the only MLS team that didn't play on Sunday. The team had to watch the match between Houston and the LA Galaxy from afar to see it earned a spot.
The Dynamo delivered for RSL, defeating the Galaxy 3-2 and thwarting Zlatan Ibrahimovic's first appearance in the MLS playoffs. Ibrahimovic did not speak to reporters following the match.
The Columbus Crew got a hat trick from Gyasi Zardes to down Minnesota United 3-2 to deny Montreal a playoff spot in the East. The Impact needed a victory over the Revolution and for Columbus to lose or draw at home to get in. Montreal fell 1-0 to the Revolution.
Third seeded NYCFC will host No. 6 Philadelphia and No. 4 D.C. United will host No. 5 Columbus in the East's knockout round matches this week. In the West, No. 3 seed LAFC hosts No. 6 RSL and No. 4 FC Dallas hosts No. 5 Portland. The specific times and dates were not immediately set.
Atlanta striker Josef Martinez officially won the league's Golden Boot award with an MLS record 31 regular-season goals, besting the previous record by four goals. Second-best scorer this season was Ibrahimovic with 22.
Two players made their final appearances with their teams on decision Day: Vancouver's Alphonso Davies scored twice in his final match, a 2-1 victory over the Timbers. Davies is off to German Club Bayern Munich.
"As a 15-year-old kid making his debut, from start to finish the fans have always supported me. When I got the news that I was signing for Bayern Munich, I just wanted to make things special because I was off the field for a while and I was missing it. So then, coming into this game, knowing it was my last game for Vancouver I just wanted to leave with a positive feeling," Davies said afterward.
Veteran forward Alan Gordon announced his retirement following Chicago's final match of the season, a scoreless draw against D.C. United.