Receiver Saubert made the decisive two-point play for Seattle.
Seattle engineered a stunning comeback to overcome the Los Angeles Rams in extra time, securing their spot in the NFL play-offs.
Rallying from a 30-14 hole in the final period, the Seattle squad triumphed 38-37 at home, registering their fifth consecutive victory.
While the Rams had already secured a playoff spot earlier on Sunday, the Seattle team secured their place to the postseason after a two-year absence.
With this outcome, the Seattle now lead their Conference race with a 12-3 mark, replacing the Los Angeles, who dropped to the number five playoff position with an 11-4 record.
Signal-caller Darnold threw two interceptions but recovered to deliver two scoring throws, culminating in the tying TD to star receiver Smith-Njigba in the extra period.
The Rams held a six-point advantage at half-time before Kenneth Walker III burst through for a 55-yard scoring dash for the home side.
Los Angeles cornerback Wallace then returned Darnold's first interception for 56 yards, setting up a one-yard score by Corum on the next play.
In the final stanza, a touchdown from Matthew Stafford to Puka Nacua extended the Rams' lead to 30-14, but Rashid Shaheed provided Seattle's hope with a 58-yard return for a score.
Darnold then found Barner in the endzone, and a converted two-point play forced the game into an extra period.
Although Nacua scored for his second TD in OT, Smith-Njigba responded in kind to setup the decisive score.
Lena Hartwell is a former statistician and lottery enthusiast who now writes about probability and smart play strategies.