OKLAHOMA CITY -- Before the tipoff Sunday night, Larry Drew said his new-look Atlanta Hawks were still trying to find their identity.
They might have found it by the time the game ended.
"I thought the guys just came in here and rolled their sleeves up and played four solid quarters, and we're just really happy that we came in here and got a win," Drew said.
Williams hit a 3-pointer and a 24-foot jumper and converted a three-point play off a driving scoop in the lane during a 12-4 push midway through the fourth quarter that put the Hawks in front to stay. Williams' two free throws made it 91-84 with 4:44 to play, and Atlanta held off a final charge by Oklahoma City.
Williams ended up scoring 14 points overall during the fourth quarter as the Hawks won their road opener despite playing without starting forward Josh Smith because of a sprained right ankle.
"We've got new faces, a new team but we stuck with the offense. We believe in ourselves," said DeShawn Stevenson, who moved into the starting lineup and got the call down the stretch as Drew stuck with a mix of starters and reserves.
"This is a great team. This is a team that could easily go back to the Western Conference finals or the Finals, and to come out here without Josh Smith is big," he added.
Kevin Martin scored 28 points off the bench to lead the Thunder and Kevin Durant chipped in 22 points, 12 rebounds and eight assists. Durant was two assists shy of his first career triple-double but also wound up with six turnovers while shooting 2-for-9 in the second half.
Fellow All-Star Russell Westbrook had an off night, making 5 of 18 shots while scoring 14 points and passing out nine assists.
The Thunder's 21 turnovers led to 31 Atlanta points.
"I wish I could have had a couple of those turnovers back," said Durant, who has 20 assists and 16 turnovers in three games this season.
Oklahoma City pulled to 91-89 after Martin's 3-pointer from the left corner got the crowd roaring with 4:06 to play. Kendrick Perkins protested after being called for a foul for hacking Devin Harris on the arm on a baseline drive, and Harris hit both free throws.
On the next trip, Westbrook tried to save a rebound under the basket but ended up feeding Horford with a behind the back pass for a dunk. Another Horford dunk set up by Zaza Pachulia and Stevenson's 3-pointer -- also off a Pachulia pass -- bumped the lead to 100-91 with 1:28 to play.
That was too much for Oklahoma City to overcome.
Williams, the runner-up for Sixth Man of the Year last season with Philadelphia, was one of several acquisitions in an offseason roster shake-up that included Joe Johnson leaving for Brooklyn.
Martin, the Thunder's new sixth man after James Harden was dealt to Houston a week ago, got it going early with 22 first-half points. But it was Williams who finished it off.
"Lou got into a rhythm. He got into a rhythm and we were going to ride it," Drew said. "I had to make a decision whether to bring (starters) Jeff (Teague) and Kyle (Korver) back, but the group that was in there, they had a good rhythm going and I did not want to do anything to disrupt that.
"So, we decided to ride Lou's hot hand and he made some really big baskets," he added. "He made some really big plays for us."
Atlanta turned 12 offensive rebounds -- six by Horford -- into 16 points.
Jeff Teague had 16 points but was replaced down the stretch by Harris, who was dropped out of the starting lineup in favor of Stevenson. Anthony Tolliver started in Smith's place, but it was Pachulia who played late and made assists on a couple key baskets.
"I thought the ball swung around a lot tonight, which shows the growth that this team has displayed over the past couple of games. Hopefully, that'll be something we can bottle up and use in the future," Williams said.
The Hawks hit four straight shots and scored 11 consecutive points to take the lead late in the first quarter, with Teague connecting on a pair of driving baskets and two free throws to make it 22-16. Atlanta's advantage reached as high as 10 after Williams' jumper in the first 2 minutes of the second quarter.
The Thunder outscored Atlanta 33-14 over the next 12½ minutes to lead 57-49 early in the second half.
"We had a lot of breakdowns. We can't start the game off in cruise mode. We've got to go take it," Durant said after his team fell to 1-2. "A team's not going to just let us feel our way into the game. We've got to go take the game.
"Early on, we just sat back and let them do whatever they wanted and that gave them confidence toward the end of the game," Durant added.
Brenda Pantoja became the third woman to officiate an NBA game, following veteran official Violet Palmer and fellow rookie Lauren Holtkamp. Holtkamp, who made her debut in the Bulls-Cavaliers game on Friday night, are two of six non-staff officials who will work games this season. Pantoja, a former Arizona point guard who holds the school's career record for assists, has worked in the WNBA and NBA development league in recent years. ... The Hawks also won last season's only meeting. ... Durant, the three-time scoring champion, came in leading the NBA with 15.5 rebounds per game.