OKLAHOMA CITY (AP) — Coming off his worst performance in the playoffs, Kevin Durant couldn't get his shots to fall again.

Then he caught a glimpse of his mother dancing around during a timeout and, like magic, the ball started going through the net.

Durant scored 39 points for his best offensive outing of the series, Russell Westbrook had his first playoff triple-double and the Oklahoma City Thunder advanced to the Western Conference finals with a 105-90 victory over the Memphis Grizzlies in Game 7 on Sunday.

"I knew she had those dance moves," Durant said. "She used to do it all the time when I was young. She was having fun. I was glad to see that."

Soon enough, he was having fun, too — and the Thunder are two-stepping into Texas for the franchise's first appearance in the West finals since losing in the NBA finals in 1996 as the Seattle SuperSonics.

Game 1 against the Mavericks is Tuesday night in Dallas, just a short drive south down Interstate-35.

Durant, the NBA scoring champion the past two seasons, followed the lowest-scoring game of his two postseason appearances with one of his best. He heated up in the second quarter after the entertaining exchange with his mother, put the Thunder in control late in the third, then put it away with a pair of two-handed slams in the fourth.

"Durant is a special player, one of the best players in the NBA," said Memphis star Zach Randolph, who was limited to an inefficient 17 points and 10 rebounds. "The kid is a gym-rat, he works hard. He's one of my favorite players. You've got to give him kudos and give him respect.

"You see what he does night in and night out and he's just relentless."

Westbrook, criticized throughout the playoffs for taking too many shots, was at his all-around best with 14 points, matching his season-high with 14 assists and producing extra possessions with 10 rebounds. It was only the fifth triple-double in a Game 7, according to information provided to the team by the Elias Sports Bureau. Larry Bird, Jerry West, James Worthy and Scottie Pippen also accomplished the feat.

"He gets picked on a little bit, but one of the things (with) Russell, he keeps playing," Thunder coach Scott Brooks said. "He keeps improving, he keeps getting better and tonight he controlled the game."

Mike Conley scored 18 points to lead Memphis, which had never won a playoff game before this year and made a bid to become the first No. 8 seed to reach the West finals.

"We just believed we could play with anybody," said Randolph, who had averaged 28.3 points and 14.7 rebounds in the Grizzlies' three wins in the series. "We've been competing like this all year. We just wasn't seen nationally and a lot of people didn't know about us because weren't on TV a lot, but we've been playing good basketball all year and competing with the best teams."

James Harden added four 3-pointers and 17 points for Oklahoma City, and Nick Collison had 12 rebounds.

O.J. Mayo scored 14 for Memphis but couldn't provide the same amount of room for Randolph as he did after moving into the starting lineup in Game 6.

It was the first Game 7 of the 2011 playoffs, and the first in the career for Durant and most other players on two of the NBA's rising teams. They were the two youngest rosters in the league at the start of last season, but have quickly become two of the best — just as some of the traditional powerhouses have declined.

"I think that age is kind of out the window now. Usually, you hear young franchise. Now, we've grown up together and we're getting better," Westbrook said.

"I think as long as we continue to stay humble and continue to work and try to get better, this team's going to make that next jump."

The first jumps have been big ones for the Thunder — from 3-29 and headed for the worst season in NBA history after moving to Oklahoma City in 2008 to the West finals just 2½ years later.

Lionel Hollins pulled the Grizzlies' starters with just over 2½ minutes left, after Durant hung on the rim and yelled after his second dunk of the closing minutes. Brooks followed at his next chance, with Durant calmly raising his right fist as he to the sidelines with the sellout crowd standing and roaring at its loudest.

Fans started chanting "We want Dallas!" in the final minute — already gearing up for series that'll be played along a stretch of Interstate 35 a little over 200 miles.

Durant came out aggressive after scoring just 11 points on 3-for-14 shooting in Game 6. He put up nine shots in the opening quarter but made only two, with Memphis leading by as many as five in the early going.

The Grizzlies then missed 18 of 23 shots over a stretch between the midway points of the first and second quarters. The Thunder took advantage with a 13-4 run to finish the first quarter with a 21-17 advantage, then extended their lead with the unexpected spark in the second.

Arena camera crews caught Durant's mother pumping her fist in the air and dancing at her courtside seat during a timeout, and the scoring champ got a kick out of it from across the court. He came out and hit a jumper in the lane and his first 3-pointer from the right side during a 9-0 burst that gave Oklahoma City its first double-digit lead at 33-23.

He also hit his next two shots — another 3 and a layup off a Westbrook alley-oop — to bump the lead up to 11 before Conley's 3-pointer got Memphis to 42-34 at halftime.

Randolph led the Grizzlies back, and Conley's 3-pointer cut it to 52-49 with 4:52 left before Durant got going again.

Durant provided eight points — including two 3-pointers — during a 14-2 response as the Thunder regained control. After his second 3, he ran screaming to the opposite end of the court and slapped hands with former Oklahoma City player Desmond Mason, who was seated courtside.

Durant added a free throw after Hollins' technical foul, and the Thunder led 66-51 with 1:24 to go in the third.

"He brought the All-Star," Memphis' Tony Allen said. "He pushed the turbo button on us today."

NOTES: Home teams are 86-21 in Game 7s in NBA history, and 58-14 since ABA-NBA merger before the 1976-77 season. ... The Thunder had been 5-8 at home on Sundays in the regular season and playoffs, and 30-4 on all other days. ... Gary Payton had the only two other postseason triple-doubles in the Thunder's franchise history, dating to its days in Seattle.