OKLAHOMA CITY -- In this first half of the season, Oklahoma City is starting to make something pretty clear. No matter who the Thunder are playing, they never have a lead that is safe.

Facing an undermanned Dallas Mavericks squad, the Thunder watched a 29-point fourth-quarter lead whittled down to 14 before finally pulling away for a 108-89 victory Wednesday at the Chesapeake Energy Arena.

"It was a difficult game for everybody," Thunder center Enes Kanter said. "I think we kept our focus. We were really good in the first half and second half on both ends. They rested their guys, but like I always say, we can't worry about what they're doing. We can only focus on what we do on the court and play basketball."

Forward Kevin Durant scored 29 points to lead Oklahoma City. He shot 9 of 14 from the field to go with 10 rebounds and four assists. Forward Serge Ibaka added 20 points and 11 rebounds as the Thunder improved to 28-12.

Playing without all five starters, the Mavericks were paced by guard J.J. Barea, who had 18 points and six assists. Guard Raymond Felton added 14 points on 3 of 11 shooting as the Mavs fell to 22-18.

But Dallas coach Rick Carlisle liked the way his team competed under difficult circumstances, especially Barea.

"It's a physical game, it's emotional, both teams competed," Carlisle said. "(Barea) is a walking breathing, stubborn, competitor. That's why he's been a really terrific 10-year player. He's not going to back down. The bigger the moment, the bigger the challenge, the more he is going to rise to it. I think we have a team of competitors."

It took a couple of minutes for Oklahoma City to get itself interested when the night started. Without Dallas having its normal cast of rivals on the court for Durant, Ibaka and guard Russell Westbrook to focus on, they came out with a lackluster look.

But the mismatches quickly started to become apparent. Felton was forced to defend Durant, who scored 11 points in the opening quarter.

The Mavericks had no players to turn to in order to change the tide. Barea tried to provide the needed offense and keep the contest close.

However, midway through the second quarter, Barea got tangled up with Westbrook and started a shoving match between the two teams and several technical fouls were issued.

"It was a regular foul, then (Westbrook) threw his arm, and then it went a little crazy after that," Barea said. "I was there. I wasn't backing down. He started pushing, I started grabbing, he grabbed me."

The altercation just seemed to motivate Durant, who then hit a pair of 3-pointers and threw down a dunk on rookie forward Justin Anderson.

The Barea-Westbrook feud flared up again late in the first half and Westbrook was hit with his second technical foul and ejected from game. However, the Thunder still led 65-42 at halftime.

"That's how Barea is. He's a chippy player," Durant said. "I mean, he has to be that way. He's the smallest guy in the league, one of the toughest guys in the league as well. So we knew he was going to try and add a little something to the game, but we did a good job keeping our heads."

With guard Devin Harris injuring his foot and forward Charlie Villanueva being ejected with two technicals, Dallas was down to eight players in the second half. Even without Westbrook to keep Oklahoma City's offense humming, they were still too much for the shorthanded Mavs.

"We got it down by 29 and got it back to 12 or 14 and they had to bring their starters back in," Carlisle said. "You have got to just keep playing and they did and I am proud of the way that our guys competed."

NOTES: After the Mavericks played an overtime game against Cleveland on Tuesday, coach Rick Carlisle decided to sit F Dirk Nowitzki, G Deron Williams, F Chandler Parsons and G Wes Matthews on Wednesday at Oklahoma City. "It's hard," Carlisle said. "There are a set of circumstances that I knew coming into the season that I knew were going to be significant. In back-to-back situations, where there are big minutes, we were going to be talking about whether certain guys should play." ... Thunder coach Billy Donovan was not happy with the team's defense during a three-game road trip. "I think we need to be more consistent on the defensive end of the floor," Donovan said. "I think the two areas that consistency probably needs to get better is transition defense and our ability to keep people off the backboard." ... After a series of late-game meltdowns this season, Thunder F Kevin Durant said he's going to reverse his trend of waiting until the fourth quarter to increase his offensive activity.