After a Kevin Durant three-pointer with 5:05 to play in regulation, the Thunder led 99-84 and looked destined to tie the series up. But somehow they ended up in overtime — how did that happen?

It was a combination of two factors: 1) Dirk Nowitzki took over offensively for the Mavs, and 2) the Thunder had several poor possessions down the stretch.

Take a look at the Mavs’ final 10 possessions:

4:48 Shawn Marion makes two free throws
4:33 Dirk Nowitzki makes 1 of 2 free throws
4:09 Dirk Nowitzki turnover
3:48 Jason Kidd makes two free throws
3:15 Dirk Nowitzki makes 13-foot jumper
2:11 Dirk Nowitzki makes 24-foot three point jumper (Jason Kidd assists)
2:00 Dirk Nowitzki makes 14-foot jumper
1:25 Dirk Nowitzki makes 5-foot two point shot
0:39 Shawn Marion makes 1 of 2 free throws
0:06 Dirk Nowitzki makes two free throws

That’s 17 points on 10 possessions, or 1.7 points per possession, which is outstanding.

Now, the Thunder’s final possessions:

5:07 Russell Westbrook misses 25-foot three point jumper
4:33 Serge Ibaka misses 6-foot jumper
4:20 Russell Westbrook misses 17-foot jumper
3:48 Russell Westbrook lost ball (Jason Kidd steals)
3:32 Kevin Durant misses 22-foot jumper
2:49 Kevin Durant misses 25-foot three point jumper
2:32 Russell Westbrook makes two point shot
2:11 Russell Westbrook misses two free throws
1:38 Russell Westbrook misses 15-foot jumper
1:07 Kevin Durant lost ball (Shawn Marion steals)
0:40 Russell Westbrook misses 16-foot jumper
0:20 Thabo Sefolosha misses 23-foot three point jumper
0:01 Shawn Marion blocks Kevin Durant’s 30-foot three point jumper

That’s two points on the Thunder’s final 13 possessions, or 0.2 points per possession. They went 1-for-11 from the field with two turnovers. Westbrook went 1-for-6 with a turnover and zero assists in the final 5:07. OKC was just unable to get good shots when the Mavs tightened up the defense in crunch time. Durant was getting pushed around while Westbrook was doing his usual dribble-around-and-fire-up-a-shot act.

Overtime was more of the same for OKC. Take a look:

4:26 Kevin Durant misses 24-foot three point jumper
3:54 Thabo Sefolosha makes jumper (Kevin Durant assists)
2:51 Russell Westbrook misses 25-foot three point jumper
2:31 Russell Westbrook step out of bounds turnover
1:54 Serge Ibaka makes 17-foot jumper (Russell Westbrook assists)
1:01 Kevin Durant lost ball (Jason Kidd steals)
0:26 Russell Westbrook misses 5-foot running jumper
0:09 Kevin Durant misses 24-foot three point jumper
0:01 Kevin Durant misses 25-foot three point jumper

Over the final 10 minutes, Russell Westbrook went 1-for-8 with two turnovers and an assist. The turnover in overtime was inexplicable. The ball was tapped back on the Mavs’ end of the court and it hit Jason Terry’s hand as it headed over towards the Dallas bench. Westbrook should have let the ball go, but instead tried to save it. It’s what I like to call “dumb hustle.”

It’s no surprise that Westbrook struggled down the stretch; it has been a common theme in these Playoffs. But Durant was pretty awful too. Here’s his line for the final 10 minutes: 0-for-6 from the field (0-5 3PT), one assist and two turnovers. Combined, the Thunder’s two stars went 1-for-14 from the field with four turnovers and two assists.

And that’s how you blow a 15-point lead with five minutes to play, only to lose in overtime. In total, they were outscored 28-6 over the final 10 minutes.