Phil Dawson kicked a 22-yard field goal with 26 seconds remaining and the Niners held off the Seahawks 19-17 on Sunday, denying Seattle a chance to clinch the division at Candlestick Park.
"We're playing for our lives," wideout Anquan Boldin said. "We're playing playoff football right now. It's win or go home."
Gore broke for his big gain with just more than four minutes left, sparking the key 11-play, 76-yard drive that helped the 49ers (9-4) stop the playoff-bound Seahawks (11-2) from grabbing away the West in San Francisco.
Dawson's fourth field goal gave him 20 successful attempts in a row, a franchise record topping Joe Nedney's 18 consecutive kicks in 2006-07.
Russell Wilson threw a 39-yard touchdown pass to Luke Willson and Marshawn Lynch ran for an 11-yard score for Seattle, denied a franchise-best sixth road victory in its fifth straight loss at The 'Stick.
"I don't know if it was their Super Bowl, but they played a great game," Seahawks defensive end Red Bryant said.
The 49ers are unbeaten at home against the West since losing to the Seahawks on Oct. 26, 2008.
In an emotionally fueled afternoon of missed chances and costly penalties, this rivalry game more than lived up to the hype.
"Enjoy it? Not the word I would use. It's like going to the dentist chair for 3½ hours and getting a root canal," 49ers coach Jim Harbaugh said. "These games are only for the tough."
Eric Wright, who briefly left the game with a head injury, intercepted a last-ditch deep pass by Wilson with 9 seconds left to seal it.
The two young quarterbacks finished with nearly the same stats. Wilson went 15 of 25 for 199 yards and a touchdown with one interception, while counterpart Colin Kaepernick threw for 175 yards and completed 15 of his 29 passes with a TD and an interception.
Vernon Davis caught an 8-yard touchdown pass just before halftime to give San Francisco some momentum.
After a home rout of New Orleans on Monday night, the Seahawks were trying to make it two mammoth wins over NFC powers in seven days. They hurt themselves several times down the stretch.
Golden Tate helped put the Seahawks ahead midway through the fourth quarter with a 38-yard punt return. Wilson then hit Jermaine Kearse for a 14-yard gain and first down from the 24. But on third down from the 13, Wilson was forced to throw out of bounds under pressure.
Seattle settled for Steven Hauschka's 31-yard field goal that stayed just inside the left upright with 6:20 remaining.
While Lynch went over 1,000 yards rushing for the third straight season and fifth in his seven-year career, he slowed down in the second half. He wound up with 72 yards on 20 carries just 22 yards in the second half as the 49ers defense kept intact its streak of not allowing a 100-yard rusher this season.
"It's December and we're playing our best football," linebacker NaVorro Bowman said. "There's something about this game that required a full 60 minutes of football."
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