Randy Bullock's last-gasp 44-yard field goal has completed the Tennessee Titans' brilliant come-from-behind 20-17 victory over the San Francisco 49ers on Thursday.

The Titans trailed 10-0 at half-time but fought back with two second-half touchdowns from D'Onta Freeman and A.J. Brown, on his return from a chest injury, to take the lead.

San Francisco quarterback Jimmy Garoppolo, who completed 26 of 35 passes for 322 yards, threw his only TD pass for Brandon Aiyuk to square the game in the fourth quarter before Bullock's late field goal with four seconds left after the Titans expertly managed the clock.

The result means the Titans can clinch the AFC South division if the Arizona Cardinals beat the Indianapolis Colts on Sunday.

The 49ers were left to rue costly Garoppolo errors, having thrown two interceptions as well as over-throwing a golden opportunity for a TD.

Ryan Tannehill managed the clock brilliantly after Aiyuk squared the game up with 2:20 left, with the Titans quarterback going on a 23-yard run in the decisive drive.

Tannehill threw 22 of 29 passes for 209 yards while Brown finished with 11 receptions for 145 yards.

The result leaves the 49ers with an 8-7 record to sit third in the NFC West.