ROUND ROCK – Plano senior middle linebacker CJ Martin and his teammates had already stuffed Spring Westfield's vaunted running game. But they needed one more big play to survive and move on in the playoffs.

Enter Martin, whose interception at the Plano 11-yard line with 3:32 left in the game put an end to a furious fourth-quarter rally by Westfield. Plano was finally able to start celebrating a 31-19 victory in a 5A Division I Region II semifinal at Round Rock ISD Stadium.

Plano (12-1) clinched its second trip to the regional finals in three years. It will play Skyline (12-1) at 2 p.m. Saturday at Mesquite Memorial Stadium.

Plano is starting to sniff a record eighth state championship.

"We're playing well enough to win it," Plano coach Gerald Brence said. "We're within days now."

Plano is halfway to a state title thanks to the efforts of Martin and several others. Plano had built a 31-6 lead and looked to be in a comfortable position entering the fourth quarter.

But Westfield (10-3) scored twice in a span of five minutes to cut Plano's lead to 31-19 and had the ball at the Plano 13 when Martin made the play of the game. Martin followed the quarterback's eyes and cut in front of Westfield receiver Adam Watson for his first interception of the playoffs.

"We were on the ropes," Martin said. "We were just a little frustrated, so we just needed to make a play."

Plano stormed out to a 21-6 halftime lead. Plano scored first for the third consecutive playoff game. After receiver Nate Christian made a key 29-yard reception, running back Rex Burkhead scored on a 1-yard run for a 7-0 lead with 9:35 left in the first quarter.

Burkhead had 92 of his 106 rushing yards in the first half.

Plano took control after Westfield missed a 23-yard field goal while trailing 7-6 with 10:07 left in the second quarter. Plano rattled off an 80-yard drive that ended on Burkhead's 17-yard run for a 14-6 lead with 7:01 left in the second quarter.

Burkhead scored his third TD and 10th of the playoffs on Plano's next possession, getting loose on a 25-yard run for a 21-6 lead with 3:44 left in the first half.

Plano kept up the pressure in the third quarter. Its special teams came up with a crucial play early in the quarter when Chris Mendenhall blocked a punt and Beau Brence recovered the ball at the Westfield 6. Plano settled for Ryan McDuff's 27-yard field goal, but it made it a three-score game at 24-6 with 8:12 left in the third quarter.