Receiver Eric Saubert executed the decisive two-point conversion for the Seahawks.
Seattle staged a remarkable comeback to overcome the Los Angeles Rams in overtime, securing their place in the postseason.
Overcoming a 30-14 hole in the fourth quarter, the Seahawks emerged victorious by a single point at home, notching their fifth consecutive victory.
While the Los Angeles had already secured a playoff spot earlier on Sunday, the Seahawks booked their return to the postseason after a 24-month hiatus.
With this outcome, the Seahawks have taken over their Conference standings with a 12-3 mark, replacing the Rams, who fell to the number five playoff position with an eleven and four standing.
Signal-caller Darnold had two interceptions but recovered to deliver two scoring throws, including the second score to star receiver Smith-Njigba in the extra period.
The Rams held a 13-7 lead at half-time before Kenneth Walker III burst through for a long scoring dash for Seattle.
Rams cornerback Josh Wallace then took back Darnold's first interception for 56 yards, leading to a short touchdown by Corum on the next play.
In the fourth quarter, a touchdown from Stafford to Puka Nacua pushed the Rams' lead to 30-14, but Rashid Shaheed provided the hope with a 58-yard return for a score.
Darnold then connected with Barner in the end zone, and a converted conversion forced the contest into an extra period.
Although Nacua raced in for his another touchdown in OT, Smith-Njigba responded in kind to set up the decisive conversion.
Lena is a tech journalist with over a decade of experience covering consumer electronics and emerging technologies.