Memphis Grizzlies Zach Randolph, middle, is fouled by Portland Trail Blazers LaMarcus Aldridge, right, as Brandon Roy, left defends during the second half of Monday's game in Memphis, Tenn. Memphis won 86-73.

MEMPHIS, Tenn. — With the game on the line, Memphis clamped down on defense, and worked the ball inside to Zach Randolph, who had 25 points and 20 rebounds Monday night as the Grizzlies held Portland to nine fourth-quarter points, defeating the Trail Blazers 86-73.

“It ain’t Chinese algebra,” said reserve guard Tony Allen, who was part of the Grizzlies’ defensive effort with two steals in the fourth quarter. “If you get stops, and you execute on offense, normally that teams wins.”

The win was the third straight for the Grizzlies, and it snapped an eight-game winning streak for Portland in Memphis. The Grizzlies hadn’t won a home game in the series in almost five years.

And, it was a typical night for Randolph, who recorded his fourth 20-20 game with the Grizzlies. It was the fifth consecutive double-double and 15th this season for the former Trail Blazer forward.

“I just try to be aggressive and hit the glass on both ends, and play around the basket,” Randolph said.

Rudy Gay added 16 points, reserve O.J. Mayo had 14 and Mike Conley 11 for the Grizzlies.

Wesley Matthews led the Trail Blazers with 18 points, while Andre Miller had 14 points and nine assists. LaMarcus Aldridge scored 13 points for Portland, which lost its second straight after a four-game winning streak.

“We had a bad fourth quarter,” Miller said. “The most important quarter, and it killed us. That was the game right there.”

Brandon Roy, who entered the game as the Trail Blazers’ leading scorer, was ineffective on a bad left knee he tweaked in Sunday’s loss at San Antonio. Roy was three of 16 from the field and scored seven points.

The Trail Blazers’ fourth-quarter production was the lowest-scoring period of the season for Portland, which put up a season-low point total for the second straight game.

Portland had only 78 points in Sunday’s loss to San Antonio. Down the stretch against Memphis, the Trail Blazers struggled.

“I think the (starting) five, those guys are gassed,” Portland coach Nate McMillan said. “I think they have played some heavy minutes. We need the bench to give us a breather. In the fourth quarter, down the stretch, we (are) not able to score late in ballgames.”

Both teams struggled early from the field, but Memphis got enough of a rhythm to push the lead to 11 points early in the second quarter.

Generally, though, it was a half with no flow. A sparse crowd in the FedExForum — announced at 10,467 — resulted in little energy in the building.

The biggest excitement came on Mayo’s 3-pointer at the horn to give Memphis a 49-42 halftime lead.

Portland erased the halftime lead, opening the third quarter with a 13-4 run. But consecutive baskets by Memphis, including another 3-pointer by Mayo, stopped the rally.

Portland still only allowed Memphis 12 points in the quarter, and the Trail Blazers carried a 64-61 lead into the final period.

But Memphis scored eight straight points to open the fourth as they began pushing the ball inside to Randolph.