Miami and Jacksonville are both 7-6, along with Baltimore, which whipped the Detroit Lions 48-3, and the New York Jets, a 26-3 winner over Tampa Bay, with three games to go in the regular-season schedule.
The four teams are behind Denver (8-5), which lost 28-16 at Indianapolis, in the AFC wild card standings.
Williams, who rushed for 108 yards, scored in the first quarter and Henne got his touchdown in the second.
Maurice Jones-Drew ran 1-yard for a score and Josh Scobee connected on a 25-yard field goal, both in the third period, for the Jaguars.
Henne finished with 21 completions in 29 passes for 220 yards, with an interception.
Josh Scobee 25-yard field goal third.
Miami is at Tennessee next week and then has home games against Houston and Pittsburgh. Jacksonville takes on unbeaten Indianapolis at home, followed by road games against New England and Cleveland.