Tight end Saubert made the game-winning two-point conversion for the Seahawks.
The Seattle Seahawks engineered a remarkable fightback to overcome the Rams in overtime, securing their spot in the NFL play-offs.
Rallying from a 30-14 hole in the final period, the Seattle squad triumphed by a single point at home, notching their fifth consecutive win.
While the Los Angeles had already secured a playoff berth earlier on game day, the Seahawks secured their place to the postseason after a two-year hiatus.
With this result, the Seattle have taken over their division's standings with a twelve and three mark, supplanting the Rams, who dropped to the number five seed with an 11-4 record.
Quarterback Darnold threw two interceptions but recovered to make two touchdown passes, including the second score to wideout Jaxon Smith-Njigba in overtime.
The Rams held a six-point lead at the break before Walker burst through for a 55-yard touchdown run for the home side.
Rams defensive back Josh Wallace then took back Darnold's initial interception for 56 yards, setting up a one-yard touchdown by Blake Corum on the next play.
In the final stanza, a touchdown from Matthew Stafford to Nacua pushed the Rams' lead to 30-14, but Rashid Shaheed ignited Seattle's hope with a 58-yard return for a score.
Darnold then found AJ Barner in the endzone, and a converted two-point play sent the game into overtime.
Although Puka Nacua scored for his second touchdown in overtime, Smith-Njigba responded in kind to setup the decisive score.