So much for the Seahawks surging into the playoffs.

With a playoff spot on the line, they put up one of their worst collective efforts of the season, letting the 10-loss 49ers beat them 26-23 in overtime and end Seattle’s 10-game winning streak in the series.

The Hawks ruined themselves by committing a season-high 14 penalties for a franchise-record 148 yards, missing an early PAT that figured huge in the end, giving up a kick return for a TD, surrendering chunks of yards in the first half and failing to finish enough offensive drives to win.

The loss means the Hawks still likely have to win one of their last two — next Sunday night vs. Kansas City or against Arizona in the finale — to reach the playoffs.

This defeat ruined a great return by Doug Baldwin, who doubled his season touchdown total with two scores vs. the 49ers. He caught four passes for 77 yards. “Doug was spectacular today,” Pete Carroll said.

The game got off to a horrible start for Seattle, which gave up eight points right after scoring early in the first quarter. First, Janikowski whiffed on the PAT, and then the kickoff team let Richie James go 97 yards, running right by Janikowski, for the tying TD.

After that, the defense let Nick Mullens, the 49ers’ third QB, drive up and down the field. The 49ers averaged 8.4 yards per play in the first half as Seattle’s linebackers and safeties repeatedly got burned by tight ends George Kittle and Garrett Celek. San Francisco led 17-13 at halftime.

The Seahawks really missed Bradley McDougald, who left in the first quarter after his knee tendinitis flared up. He had forced a fumble early in the game. Delano Hill and Tedric Thompson had issues covering the tight ends after he left.

Baldwin and Chris Carson did their best to help the Seattle offense. Carson ran for 119 yards on 22 bruising carries and scored on a beastly fourth-down effort early in the fourth quarter.

THE EFFORT!

💪 @ccarson_32

📺: FOX
WATCH: https://t.co/3jJ7T6kh4h #Seahawks pic.twitter.com/UKfY7y7F68

— NFL (@NFL) December 16, 2018

The offense suffered a big blow when right guard Jordan Simmons left with a sprained knee. One-time starter, now No. 4 guard, Ethan Pocic struggled mightily in the run and pass. He was called for two holds — the second negating a great third-down hookup between Russell Wilson and J.D. McKissic in overtime.

The 49ers took the ball next and moved 44 yards to set up Robbie Gould for the 36-yard kick to end the 49ers’ losing skid vs. Seattle. The Niners were helped by a 15-yard pass-interference call against Shaquill Griffin that the cornerback called “terrible.”

That capped a record day for the Hawks, whose 14 flags tied for third most in franchise history, along with the team-record 148 yards.

Those penalties, along with the two big special-teams gaffes and the key injuries, added up to the worst loss by Seattle since the 2017 season finale against Arizona in Seattle.

If the Hawks can’t beat the Chiefs on Sunday night, they will need to beat Arizona in this year’s finale or risk missing the postseason for the second straight year.

OTHER OBSERVATIONS

Michael Dickson had another amazing game, averaging 53.3 yards on eight punts, with a long of 65, and twice dropping kicks at the 1-yard line. Pro Bowl, here he comes.

Jarran Reed had two sacks, bumping him to 8.5 this season. He had just three in his first two years. Imagine if the Hawks can add another pass rusher to go with Reed and Clark in the offseason.

How big were the mistakes made by the Hawks? They lost despite winning the turnover battle (1-0) and time of possession (37-30), rushing for 168 yards and converting 9 of 19 third downs.

The Seahawks have to find a starting-caliber safety in the offseason because (1) they might not be able to count on McDougald full time or for a long time and (2) Hill and Thompson have not made enough plays for Carroll and the coaches to be confident they are the future.

The Seahawks also will need a new kicker. Janikowski has factored in two or three losses — and his two misses were part of the reason Seattle needed him to kick a last-play winner at Arizona. He has been better than Blair Walsh, hitting a couple of game-winners, but the Hawks need to upgrade at kicker next year.

There’s a chance the Hawks can get in the playoffs at 8-8 — they own most of the NFC tiebreakers.