Reserve guard Jordan Poole had 31 points, nine rebounds and eight assists to power Golden State over Memphis 117-116 in an NBA playoff series opener Sunday despite the ejection of Draymond Green.
Klay Thompson sank the decisive 3-pointer with 36.6 seconds remaining and the Warriors denied Grizzlies playmaker Ja Morant twice in the final seconds.
"Big win for us to start the series, get home court advantage," Warriors guard Stephen Curry said. "And get greedy in the second game."
The Western Conference second round best-of-seven matchup will continue Tuesday at Memphis.
In Sunday's Eastern Conference opener, Milwaukee's Giannis Antetokounmpo delivered a triple double with 24 points, 13 rebounds and 12 assists as the defending champion Bucks won 101-89 at Boston.
At Memphis, Curry added 24 points for Golden State while Andrew Wiggins had 17 and Thompson 15.
Morant had 34 points, 10 assists and nine rebounds and Jaren Jackson had 33 points and 10 rebounds for Memphis.
The Warriors were delivered a major setback when forward Green, a star defender in Golden State's title runs in 2015, 2017 and 2018, was ejected in the second quarter for a flagrant-2 foul, striking Brandon Clarke in the face and pulling him down by the jersey.
"This is a huge game to win, especially with him going out early," Poole said. "We were able to fill in for the energy he has."
The Warriors responded with a strong third-quarter start.
"We were determined," Warriors coach Steve Kerr said. "We knew that was a tough break that didn't go our way. We were shocked by the decision. We went on a run in the third quarter to get the lead. That established we weren't going anywhere."
Poole scored a playoff career high in 38 minutes off the bench, hitting 12-of-20 from the floor and 5-of-10 from 3-point range.
"He's a hooper, ultimate confidence in himself," Curry said. "You can't teach that preparation for the moment. You either have it or you don't and he does."
Poole led the Warriors with 14 first-half points and added 10 in the third quarter as Golden State took a 91-90 lead.
"At the core we've got championship DNA and we want to utilize that," Curry said. "At this stage that's what it's all about."
Poole scored seven points in a 12-3 run to open the fourth and give the Warriors a 103-93 lead before the Grizzlies battled back.
Thompson missed two late free throws and Memphis had a final shot but Morant missed a driving layup at the buzzer.
"He had a great look. It just didn't happen to go in," Memphis coach Taylor Jenkins said. "I love the way our guys competed. It just wasn't good enough."
- Giannis aggressive -
At Boston, Antetokounmpo scored or assisted on 55 of 87 Milwaukee points made when he was on the court against the NBA's top defenders.
"I just like to be aggressive," said Antetokounmpo. "I want to be aggressive. My teammates want me to be aggressive. I'm trying to get into the paint for my teammates and for myself."
Antetokounmpo made three turnovers in the first five minutes as Boston used multiple defenders to guard the Greek giant.
But from there, Antetokounmpo was able to lift the Bucks despite Milwaukee playing without forward Khris Middleton due to a sprained left knee ligament.
Milwaukee's Jrue Holiday scored a game-high 25 points with 10 rebounds while Bobby Portis added 15 points and 11 rebounds as the Bucks kept it intense and physical.
The Celtics shot a woeful 28-of-84 from the floor (33.3%) and made only 10 baskets inside the 3-point arc while attempting a team playoff record 50 3-point shots.
"It's good to get this dud out of the way," Celtics coach Ime Udoka said.
Udoka was unhappy about the Bucks scoring 27 points off 18 Celtics turnovers and said Boston's inability to score inside was "alarming."
"We settled for some tougher 3-point shots," he said. "For the most part I don't think our decision making was great."
Boston's NBA Defensive Player of the Year Marcus Smart suffered a right shoulder injury and thigh bruises in the second quarter.
Jayson Tatum led the Celtics with 21 points.