Ryan Tannehill threw for two touchdowns Sunday, and the Tennessee Titans’ maligned defense played one of its best games of the year in a 24-17 win over the struggling Chicago Bears in Nashville, Tenn.Tannehill completed just 10 of 21 passes, but for 158 yards with no interceptions. NFL rushing leader Derrick Henry was held to 68 yards on 21 carries for Tennessee, which gained a season-low 228 total yards.But the Titans’ defense came up big against one of the league’s weaker offenses. Tennessee held Chicago off the scoreboard through three quarters while posting a season-high three sacks. The Titans entered the game with only seven.Tennessee (6-2) also limited the Bears to 2 of 15 on third down after entering the day allowing opponents to convert a league-high 61.9 percent, the worst mark for an NFL defense since 1991.Chicago quarterback Nick Foles connected on 36 of 52 passes for 335 yards, including fourth-quarter touchdown passes to Ryan Nall and Jimmy Graham. But it wasn’t enough to keep the Bears from falling to 5-4, 1 1/2 games behind first-place Green Bay in the NFC North.Stephen Gostkowski initiated scoring for the Titans with a 40-yard field goal at the 4:22 mark of the first quarter. Tennessee increased the lead to 10-0 with 4:39 left in the first half as Tannehill found A.J. Brown for a 40-yard touchdown, dropping a pass over tight coverage from Buster Skrine.