Updated

The minutes and demands seem to be piling up on Oklahoma City star Kevin Durant.

And despite finally getting help from his teammates on Monday night, the Thunder still find themselves on the precipice of elimination from the Western Conference playoffs.

Durant had 27 points to lead the Thunder, but he was only 5 of 17 after halftime as Oklahoma City lost in overtime to the Memphis Grizzlies 103-97. The defeat put the defending Western Conference champs down 3-1 as the best-of-seven semifinal heads back to Oklahoma for Game 5 on Wednesday night.

"I'm giving everything I've got for my team no matter how many minutes I play," Durant said. "And that's what I've been doing since the playoffs started so you know no matter how the game goes, I'm going to fight and claw for my teammates every minute I'm on the floor."

Durant averaged 44 minutes through the first three games of the series and played more than 48 minutes in Game 4. But he said all the right things about whether fatigue is setting in as he tries to take over the leadership role he usually shares with point guard Russell Westbrook, who is out after suffering a knee injury in the opening round series against the Houston Rockets.

Asked about all the extra playing time, Durant glanced at the clock, and said: "Well it is midnight, and my bedtime is usually around 12 o'clock or so. I'm a little sleepy because it's past my bedtime, but other than that, I'm good."

Durant did get more help from his teammates Monday night. Forward Serge Ibaka, who has struggled at times in the postseason, matched his high-point performance in this postseason with 17 points, while also grabbing 14 rebounds. Kevin Martin scored 18 off the Thunder bench, while Westbrook's replacement, Reggie Jackson had 15 points and eight assists.

The overtime period was where things fell apart for Oklahoma City, just as it did down the stretch in Games 2 and 3. The Thunder made only one of eight shots in the extra frame - a 3-pointer by Derek Fisher with 1:56 left - and never had a lead after Memphis opened overtime with inside baskets by Tony Allen and Zach Randolph.

The game closed with Durant missing a layup with about 3 seconds left, his fifth miss without a basket after the end of regulation.

"He's an aggressive player," Thunder coach Scott Brooks said. "I have to do a better job of putting him in a better position where he gets to the paint and draws some fouls and gets to the free throw line."

Oklahoma City dominated most of the first half, building the lead to 17 before a late Memphis burst carved the advantage to 56-48 at halftime.

After the break, Memphis began clamping on the defense, holding the Thunder to 41 points, including overtime. Oklahoma City hit 13 of 40 after the break and committed seven turnovers.

Offensively, the Thunder had no answer when Memphis pulled away in overtime.

The Thunder, however, was still within one possession and inbounding the ball with 22 seconds left when Allen made his third steal of the game on Fisher's inbounds pass. Memphis then closed the game with free throws.

"We tried. We tried so hard," Ibaka said, later adding: "We know how focused we need to be for the next game. The series isn't over. We know how our focus needs to be to get one more win in Oklahoma City."

The Thunder know they will have their crowd behind them on Wednesday night. Brooks said this series isn't over. Yet.

"It's the first to four," Brooks said. "They're in a good position, but our challenge is not impossible. It's something that we can do. We just have to focus one possession, one game at a time. Hopefully, we can do that and come back here Friday night. There's a barbeque festival right?"

Mike Conley led Memphis with 24 points and Marc Gasol and Randolph each had double-doubles. Randolph had 23 and 12, while Gasol had 23 and 11 along with six blocks on the day the Defensive Player of Year was named to the NBA's second All-Defensive team along with Conley, who had four steals.

Allen, who finished with 10 points, had three steals on the day he edged LeBron James for most points for the NBA's All-Defensive team.

Memphis outscored the Thunder 28-10 in the third quarter to get back into the game. The Grizzlies had a chance to close out the win when Ibaka blocked a shot by Randolph just before the buzzer in regulation before doing just that in overtime.

The Thunder spent most of the past two days talking about the need to make shots. They did just that to open the game, hitting three of their first five in scoring the first seven points and led 29-18 at the end of the first quarter for their biggest lead in this series. Ibaka found his shooting stroke after struggling through this series, and he had nine points in the first 12 minutes, including a 3-pointer, with seven rebounds.

Oklahoma City had its biggest lead on a corner 3 by Durant that gave Oklahoma City a 46-29 lead with 4:26 left in the second quarter.

Memphis showed signs of life trimming the Thunder's lead to 56-48 at halftime. Oklahoma City thought it had a double-digit lead when Ibaka beat the buzzer with a putback off a missed Durant 3. But officials reviewed the play and waved the bucket off.

Tayshaun Prince said the Grizzlies talked at halftime in the locker room happy to get it under 10. The pep talk was simple.

"We just told ourselves: 'Look, we can't play no worse than we did in that first half,'" Prince said.

Notes: The Grizzlies sold out their 15th straight postseason game. ... All three Grizzlies' wins in the series have been by six points each. ... The Thunder now have lost three straight. They lost three straight only once during the regular season. ... The Grizzlies have won 11 games when trailing by at least 17 points since Hollins' first season as head coach in 2009-10. That's the most in the NBA in that time.