It’s a hackneyed old turn of a phrase, but it’s worth using in this case: You can’t spell Gardendale without “D.”

And the visiting Rockets couldn’t have shut out Center Point and secured a berth in the Class 6A playoffs without their “D,” as in defense. It’s what pushed Gardendale to a 17-0 win over the Eagles Friday night.

Out of 36 rushing plays, the Rockets held Center Point to no gain on five and forced a loss on 17 plays. That included two separate three-and-out possessions for the Eagles in which five plays were for minus yardage, and the sixth was a no-gain.

It was the Rockets’ best defensive effort of the season, which helped make up for an offense that was not as potent as coach Matt Plunkett had hoped for.

“We didn’t play well offensively at all. We’ve got to get better up front,” Plunkett said. “The offense struggled a bit, but we’ll answer those questions later, and fix the mistakes we made. But we’re really proud of our defense for stepping up and containing them, because [Center Point] had some athletes.”

The one that gave Plunkett a case of the nervous Nellies was Eagle quarterback Keilan Knight, who has proved his moves numerous times in the backfield. But Gardendale made him a non-factor with heavy pressure, which resulted in five sacks and two other minus-yardage plays. The last of those resulted in him limping off the field with four minutes left in the third quarter; he did not return.

Knight’s replacement, sophomore Chris Baker, didn’t make Plunkett feel any better then the substitute proved his ability to scramble out of trouble late in the game.

Gardendale struggled a bit in the early going, escaping with a Demetrius King interception in the Eagles’ red zone but failing to take advantage.

The Rockets got on the scoreboard early in the second quarter, when quarterback Zac Cupps connected with Austin Hicks, who pulled down a leaping catch in the back opposite corner of the end zone for a 12-yard touchdown with 10:36 left in the quarter.

Gardendale’s only other touchdown came on special teams, as Knight — also the Center Point punter — drilled a kick right into the backside of one of his blockers. King picked up the loose ball and ran 13 yards for a touchdown with 2:41 left in the half.

The Rockets added a late field goal when Set Reburn put the ball through the goalposts from 22 yards away with 9:13 left in the game. Reburn had earlier kicked it wide from 33 yards away, and hit the upright from 30 yards.

Tye Dunklin ran for 102 yards on 12 carries. DeQua Houston, coming back from an injury, added 56 yards on 13 carries; he was the only Rocket to gain yardage in the third quarter.

Aside from the touchdown pass to Hicks, Cupps did not have the best of nights. He completed just four passes of 18 tries, all in the second quarter. Backup Blake Zumbado played in the fourth quarter and completed his only pass attempt, for combined total of 60 yards. Hicks had two receptions for 30 yards.

But the Gardendale defense reduced Center Point’s offense to just double digits — 46 yards on the ground, 49 in the air for a total of 95 yards. And they gave back 85 of those yards on 10 penalties.

Andrew Freeman led the Rocket defense with eight tackles, two assists, two sacks and a forced fumble. Justin Fillmore added seven tackles and two sacks, plus a fumble recovery. Juan Jackson also recovered an Eagle fumble.

The win guarantees Gardendale (3-1, 3-0 region) at least a fourth seed in the playoffs. They’ll likely move up to third with a win over lightly-regarded Woodlawn, even if the Rockets fall to second-ranked Clay-Chalkville (which had a close call from Pinson Valley on Friday) and No. 3 Shades Valley. They’ll host Minor in a non-region game next week.

Center Point (1-3, 1-2 region) will need to knock off both Pinson Valley and Huffman to secure a playoff berth. They travel to Parker next week in out-of-region play.