Predictably, the San Antonio Spurs beat the Dallas Mavericks in game 1 of their Western Conference quarterfinal series on Sunday. How it happened, well, that was much less predictable. Who would have thought it would be the Mavericks’ offense that would betray them?

The Mavs were up, 81-71, with 7:45 left in the game. Now, you couldn’t say the Mavs were in control of the game because, you know, it’s San Antonio, and the Spurs had beaten the Mavs nine straight times entering the playoffs. But the Mavs were in great shape.

Then the bottom just dropped out inexplicably. Sure, you can make hay about the resurgence of Tim Duncan and Tony Parker in the final seven minutes offensively or the Mavs’ turnovers. But let’s face it. Their own shooting is what killed the Mavs in this one.

From 7:45 to the end of the game, the Mavs shot 1-of-13 from the floor. That included missing three point-blank layups. The Spurs ended up going on a 19-4 run to end the 90-85 victory.

Let’s put this in perspective. The Mavs shot 41 percent for the game. Had they been able to shoot 41 percent in those final seven minutes, the Mavericks could have stole one in San Antonio.

The Mavs are one of the best three-point shooting teams in the NBA. They hit six of them on Sunday afternoon. But the Mavs whiffed on five of them in the final seven minutes. Had they hit just two of them, they would have won.

The Mavs received a boost from the bench Sunday afternoon. While both Dirk Nowitzki and Monta Ellis struggled to score 11 points each, guard Devin Harris scored 19 points and helped the Mavs to a slim halftime lead. Brandan Wright strolled in to score 11 points and Vince Carter had 10. Meanwhile, Manu Ginobili was the Spurs’ only significant bench player on Sunday.

But you can't do it all from the bench. Harris scored the only field goal in that final 7:45, a garbage layup at time expired. Wright's free throws were the only other two points in that stretch, and he missed a pair from the charity stripe as well.

The Spurs looked a tad vulnerable on Sunday, especially in the fourth quarter when Duncan went to the bench and Parker practically disappeared. During that time, the Mavs built that 10-point lead. But when you play a team that looks vulnerable you must close the deal, especially one with the wealth of postseason experience the Spurs possess.

“We have to do better as a team,” Mavs head coach Rick Carlisle said after the game. “We can’t just blame it on [Tim] Duncan coming back in the game. We have to move the ball better, knock down open shots, and if we miss, we have to get back and get stops. Closing games is more about getting stops than shot making, even though they’re both important. If you build a lead, you have to close it.

The Mavericks didn’t — but not because of their questionable defense but because of their suddenly impotent offense. Game 2 awaits Wednesday night. Perhaps the Mavs can get the lid off the basket by then, or else this will be a short series.