With loss to Thunder, Mavs once again can't keep pace with a vulnerable contender

Sue Ogrocki/AP

Oklahoma City Thunder guard Russell Westbrook was a beast in the third quarter as the Thunder overran the Mavericks. (AP Photo/Sue Ogrocki)

OKLAHOMA CITY -- For the second time in as many nights, the Mavericks had a high-profile opponent in their crosshairs.

For the second time, they misfired in the third quarter and, ultimately, squandered a chance for a win against an opponent that has not yet found a rhythm.

But the Thunder did have Russell Westbrook, who scored 16 points in the third quarter when the Mavericks fell behind by 16. They never could mount a serious rally and fell 112-99 Sunday at Chesapeake Energy Arena.

Westbrook finished with 27 points, but it was Paul George…