But they didn't because JR Smith lost his mind at the worst possible time and referees made a huge, controversial change on a call that helped swing the game the Warriors' way.
Golden State dominated overtime and won Game 1, 124-114, despite a playoff-career-high 51 points from LeBron James.
Stephen Curry led Golden State with 29 points and Kevin Durant added 26. The Warriors scored the first nine points of overtime and never looked back. It ended with Tristan Thompson being ejected and shoving the ball in Draymond Green's face, and then inviting him to fight in the tunnel afterwards.
It might be a while before the Cavs can bring themselves to look forward.
George Hill made one free throw with 4.7 seconds left to tie the game at 107 in the fourth quarter, but was short on the second. Smith grabbed the rebound in the paint, but instead of going back up for what could've been the game-winning layup, he dribbled the ball out as though the Cavs were ahead.
By the time he gave up the ball it was too late to get off a shot, bringing a devastating end to a fourth quarter that could've ended so gloriously for the Cavs.
"I knew it was tied," Smith said. "I thought we were going to take a timeout because I got the rebound. I'm pretty sure everybody didn't think I was going to shoot it over KD right there."
Asked about any conversation he had with Smith after the game or the play to determine what happened, Cavs coach Tyronn Lue said Smith "thought the game was over ... thought we were up one."
But Lue later clarified through a Cavs' spokesman that he hadn't spoken with Smith.
Instead, the Warriors, who are historically lopsided favorites to win this series, took Game 1 over the Cavs for the fourth consecutive year. No two teams had ever competed against each other for a championship in four straight years in any major professional sport until now.
Golden State won it all in 2015 and 2017; the Cavs claimed the trophy in 2016.
"We got to move on," James said. "You take it all the way through the night thinking about it and ways you could've been better and plays that could've happened that could've gone your way. ... You wake up with a fresh mind and you move forward."
James, playing his 101st consecutive game (a personal record for games in a season) tied Michael Jordan (109) for the most 30-point playoff games of all time and registered his eighth 40-point game in the playoffs.
James was 19-of-32 from the field with three 3s, eight rebounds, and eight assists. He committed five turnovers, and was at the center of an earlier play in regulation that killed the Cavs.
Referees originally ruled that James took a charge on Durant with 36.4 seconds left and the Cavs ahead 104-102. But, citing a rule that allows them to review block/charge calls inside of two minutes if there is question as to whether the defender is inside the circle, they reviewed it and changed the call to a foul on James. Durant responded with two free throws to tie it.
James was clearly outside the circle.
"I thought I read that play just as well as I read any play in my career," James said. "I seen the drive, I was outside the charge line, I stepped in, took the contact. It's a huge play. It's a huge play."
James, who scored 11 in the fourth, responded with a layup for another two-point lead, and Curry's layup and free throw with 23.5 seconds remaining putting the Warriors ahead by a point. Hill's missed foul shot and Smith's gaffe followed.
Kevin Love returned from a concussion to score 21 points with 14 rebounds. Smith added 10 points, and in his first Finals game Larry Nance Jr. added nine points and 11 boards. Klay Thompson added 24 points and Green contributed 13 points, 11 boards, and nine assists for the Warriors.
With 6:17 left in the first quarter, Smith dove for a steal attempt and crashed into Thompson's left leg. Thompson crumpled and limped to the locker room, but returned to the game after what the Warriors called a leg bruise. He was back on the court for the start of the second quarter.
The Cavs took a 30-29 lead into the second behind fast starts from James (12 points) and Love (nine). Curry opened the game 4-of-5 shooting for 11 points. Cleveland led 51-40 with 5:02 left before turnovers, missed shots, and Curry burned them.
The Warriors closed the half on a 16-5 spurt. Cleveland committed four turnovers during that five-minute stretch and missed six shots. Jeff Green missed a 3 with five seconds left, and the Warriors got it to Curry for a 38-footer at the buzzer and a 56-all tie.
Golden State entered Game 1 a whopping plus-130 over their opponents in the third quarter this postseason, and plus-501 in the third when combining the regular season and playoffs. The Warriors outscored the Rockets by 63 points total in the Western Conference finals, and by 68 in the third alone.
Here, the carnage wasn't nearly so bad — just an 84-78 lead for the Warriors headed to the fourth — but the Cavs once again closed the period poorly. James' 3-ball with 4:16 left put the Cavs ahead 73-70, and Golden State finished the quarter on a 14-5 run.
Game 2 is at 8 p.m. Sunday at Oracle Arena.