Tucker raised both arms in celebration as his fourth field goal of the day split the uprights with plenty of distance. The Ravens improved to 3-0 for the third time in franchise history and first since 2009.
The Jaguars fell to 0-3 for the third time in the last four years and surely will hear more talk about coach Gus Bradley's job security. Bradley is now 12-39 in four seasons, the second-worst winning percentage of any NFL coach with at least 50 games.
Tucker also made kicks of 43, 42 and 37 yards.
The Jaguars had plenty of chances to win this one in a wild fourth quarter. They forced three consecutive turnovers in the final frame, but only got a field goal out of it. Blake Bortles threw two interceptions that ended drives in Baltimore territory, and Jason Myers had a 52-yard field goal blocked.
Copyright 2016 by The Associated Press.