Cretin-Derham Hall’s Section 4, 6A first-round game against Woodbury — a team they had throttled Oct. 12 — was supposed to be just a warmup.

After all, the Raiders had rescued their season with an impressive four-game stretch over the second half of the season, outscoring opponents 194-48. Another strong postseason looked certain.

Problem is, that message never made it to Woodbury, which pulled off a huge upset 21-14.

With running back Quran Al-Hameed back after missing five games with an injury, the Royals proved to be a much more formidable foe than expected.

Cretin-Derham Hall moved downfield smartly on its opening drive, scoring on a 9-yard pass from Conor Rhoda to Connor Keane. The extra point was missed, but, at the time, that seemed to be trivial. More points were sure to come.

How wrong that assumption turned out to be. Buoyed by Cretin’s penchant for mistakes — the Raiders had four more forays into Woodbury territory, only to come up blank — the Royals appeared to gain confidence with each possession.

They took the lead 7-6 on a 4-yard run by quarterback Sawyer Moon, set up by a 46-yard pass from Moon to Reid Peters.

Another Cretin mistake — this time a fumble by James Onwualu — led to Woodbury’s second touchdown, a spectacular run by Al-Hameed. He veered right into the teeth of the Cretin defense, spun, broke two tackles, ran through two more and outraced the defense to the end zone for an 18-yard touchdown run.

Cretin responded, tying the game 14-14 on their next possession on a 1-yard run by Onwualu and a two-point conversion reception by Luke Hamel.

Undaunted, Woodbury drove to the Cretin-Derham Hall one, then punched it in after four tries on a run by Moon, retaking the lead 21-14.

The Royals then came up with the biggest stop of the game, intercepting Rhoda at their own goal line on fourth-and-five after the Raiders had driven to the Woodbury 13.

Momentum clearly on its side, Woodbury clinched the victory on the ground. With the Royals’ line blowing open huge holes, Al-Hameed and Moon found plenty of running room in the Cretin-Derham Hall defense, moving down the Raiders’ 12-yard line in the final minute.