The showdown for NFC supremacy instead turned into a showcase for the Seahawks.

And in the process of all-but-clinching home-field advantage in the NFC throughout the playoffs with a dominating 34-7 victory over the New Orleans Saints, the Seahawks also sent another loud message about their place atop the NFL hierarchy — just in case their league-best 11-1 record hadn’t already said enough.

With the victory in front of a CenturyLink Field record crowd of 68,387 that also set another Guinness noise record, Seattle officially clinched a playoff berth and took a two-game lead on the Saints and Carolina Panthers (each 9-3) with four games to play in the race for the best record in the NFC.

But having already beaten both the Saints and the Panthers, the Seahawks essentially have what is a three-game lead on the field in the NFC, and seem almost assured now of being at home for the playoffs in CenturyLink Field, where they have won a franchise-record 14 in a row.

And that’s got to be a frightening prospect for the rest of the conference after the way the Seahawks toyed with the Saints in a highly hyped Monday night game that was never in doubt.

The Seahawks — showing no signs of rustiness following their bye and no signs of distraction after the suspension of defensive back Walter Thurmond — used a flurry of big plays on both sides of the ball to jump on the Saints early and often, grabbing leads of 17-0 at the end of the first quarter and 27-7 at halftime.

From there, they cruised to their seventh consecutive victory, and 16th in 17 regular-season games dating to last year

Seattle scored on all four of its first-half possessions — two touchdowns on passes from Russell Wilson and two Steven Hauschka field goals — and also got a 22-yard return of a fumble by Michael Bennett to blow the game open early.

Given the opponent and setting, it was Seattle’s best half of the season as the Seahawks had 315 yards to just 90 for the Saints, who came in allowing 309.9 and gaining 415 per game, each among the top five in the NFL.

Wilson was almost flawless in the first half, completing 14 of 19 passes for 226 yards with a passer rating of 148.1 — a perfect rating is 158.3.

The Seahawks finished the half with a dagger of a drive, moving 88 yards in 12 plays in the final 1:52. The key play was a 19-yard completion to Jermaine Kearse on a third-and-nine from their own 13 after the Saints had called time out in an attempt to get the ball back.

From there, Seattle moved swiftly down the field with Wilson capping the drive with a 4-yard pass to a wide open Doug Baldwin to make it 27-7 at halftime.

Proof that it was simply Seattle’s night came midway through the third quarter when a Wilson pass deflected off the hands of tight end Kellen Davis and directly to Derrick Coleman, who caught it and dove into the end zone to make it 34-7.

Seattle set the offensive tone from the start, moving 61 yards the first time it had the ball to set up a 26-yard Hauschka field goal to take 3-0 lead with 7:47 left in first quarter.