Receiver Eric Saubert made the game-winning two-point play for the Seahawks.
Seattle staged a stunning comeback to defeat the Rams in extra time, clinching their spot in the postseason.
Rallying from a 30-14 deficit in the fourth quarter, the Seattle squad triumphed 38-37 at home, notching their fifth consecutive win.
While the Rams had become the first to earn a post-season berth earlier on game day, the Seahawks booked their return to the postseason after a 24-month hiatus.
With this result, the Seahawks have taken over their Conference race with a 12-3 record, replacing the Los Angeles, who fell to the number five playoff position with an eleven and four standing.
Quarterback Darnold had two interceptions but regrouped to make two scoring throws, culminating in the second score to wideout Smith-Njigba in overtime.
The visitors held a six-point lead at the break before Kenneth Walker III broke free for a long touchdown run for Seattle.
Los Angeles cornerback Wallace then took back Darnold's initial pick for a big return, leading to a short score by Blake Corum on the next play.
In the fourth quarter, a touchdown from Stafford to Puka Nacua extended the Rams' lead to 30-14, but Shaheed ignited the comeback with a spectacular punt return.
Darnold then found Barner in the end zone, and a successful conversion forced the game into overtime.
Although Puka Nacua scored for his another touchdown in OT, Smith-Njigba answered in kind to setup the decisive conversion.
Tech enthusiast and smart home expert, dedicated to simplifying innovative living.