FOXBOROUGH, Mass. — The New England Patriots’ quest for a record seventh Super Bowl championship ended abruptly Saturday night at Gillette Stadium with a 20-13 upset loss to the Tennessee Titans in the wild-card round of the N.F.L. playoffs. The defeat for the defending Super Bowl champions was a startling setback at home, where New England has won 20 out of 24 postseason games over the last two decades.

The defeat may signal the beginning of the end for the celebrated Patriots partnership between Coach Bill Belichick and quarterback Tom Brady, a combination that has made the team America’s foremost sports dynasty of this century.

If it was Brady’s last game, the final play of his career will have been a pick-six from his own 1-yard line on a night that belonged to Tennessee’s Derrick Henry, who ran for 182 yards and one touchdown.