The Washington Redskins drew 27-27 with the Cincinnati Bengals after overtime at Wembley, in front of 84,488 fans.
Running back Jeremy Hill scored a touchdown with just under seven minutes remaining in the fourth quarter to put the Bengals ahead by three points.
But Redskins kicker Dustin Hopkins scored a 40-yard field goal to send the game into overtime.
With the game in sudden death, neither side could make the breakthrough, with Hopkins missing a field goal attempt.
It was the first time an NFL game held in London has gone into overtime - a run of 16 games going back to 2007.
It was the last of three matches played at Wembley this season as part of the NFL International Series.
But the NFL has announced that Miami Dolphins will play the New Orleans Saints in London in 2017.
Late drama at Wembley
The Redskins had led 10-7 at break, but touchdowns from Tyler Eifert and quarter-back Andy Dalton gave the Bengals a 20-10 lead.
Jordan Reed and Jamison Crowder replied for the Redkins before Hill edged the Bengals in front.
Hopkins' three points then sent the game into overtime, a 15-minute period during which, once each team has had the opportunity to take possession, the first team to score wins.
Hopkins thought he had won it for the Redskins, but the Bengals called a time-out on his run-up and his field goal was not counted.
He then hooked his second attempt wide as the game ended in a tie.