Dolphins rookie QB Ryan Tannehill flashed his immense potential as he guided Miami to a dominating, 24-3 win over Jacksonville on Sunday at Sun Life Stadium in Miami Gardens, Fla.

Tannehill completed 22 of 28 passes for 220 yards with two touchdowns as he also ran for 52 yards on eight carries. The Dolphins (6-8) were delighted to see Tannehill shed his bulky knee brace in the second half as he looked more fluid. OC Mike Sherman used his young passer’s mobility by routinely rolling the pocket and calling multiple bootlegs and play-action passes.

This also took the pressure off a very young offensive line and allowed tackles Jonathan Martin and Nate Garner to get into better position for pass protection. The offensive line allowed only one sack as it paved the way for 180 yards rushing on 36 carries.

Meantime, the Jaguars (2-12) held the ball for a mere 24:22 and routinely killed drives with bad penalties.

Jacksonville appeared poised to take the lead in the second quarter after a Tannehill fumble, but an illegal substation call wiped out a 20-yard touchdown pass from QB Chad Henne to WR Justin Blackmon. The Jags never recovered, and they were stopped on fourth down in the red zone three times.

When the game turned: The Jaguars trailed 16-3 early in the fourth quarter when the team faced fourth-and-one at the Dolphins’ 15-yard line. Jacksonville brought in the power package, but RB Montell Owens was stuffed for no gain by backup LB Jason Trusnik. Miami responded with a 14-play, 85-yard drive that took 9:01 off the clock and ended with a 2-yard touchdown pass from Tannehill to TE Anthony Fasano to secure the win.

Highlight moments: The Dolphins opened the scoring with a 4-yard touchdown pass from Tannehill to FB Jorvorskie Lane with 1:56 left in the first half on a nifty bootleg near the goal line. … Blackmon had a great catch for 38 yards, and WR Cecil Shorts III had a fantastic snag for 30 yards. … Dolphins P Brandon Fields failed to execute a fake field goal in the third quarter when Fields, the holder, threw a pass 10 yards over the head of the nearest receiver.

Top-shelf performances:

What they said:

(All quotes from the Associated Press)

  • Tannehill on throwing two touchdowns in one game for just the second time this season: "It feels good to go out and execute the game plan, have some fun, have some long sustained drives and convert third downs. It was a lot of fun."
  • Jaguars coach Mike Mularkey on a touchdown negated due to an illegal substation penalty on OT Guy Whimper: "He reported to the offense a hundred times this year and 400 times in practice. Today, for some reason, I was told he didn't report. He said he reported, but the official has to confirm it."
  • Mularkey on the Jaguars amassing 10 penalties for 88 yards: "We were not as disciplined as we have been -- or we will be. Every time we take a step forward, we take two steps back. I take total blame for that.”

Numbers you should know: Hartline cracked the 1,000-yard receiving mark for the first time in his career. Bush is just 105 yards away from his second-straight 1,000-yard rushing season. He is averaging 4.5 yards per carry this season.

Injury update: Dolphins -- DB Chris Clemons left with an upper body injury in the first half but returned. DB Nolan Carroll suffered an apparent knee injury and did not return. His status is unclear. Jaguars: None reported immediately after the game.

Going forward: Jaguars -- Jacksonville lost its third straight and for the 10th time in its past 11 overall. The lowly Jags host AFC-power New England next week before wrapping up a disappointing season against the Titans in Nashville in Week 17. Dolphins -- Miami remained on the cusp of the playoff chase with a crucial victory. Lowly Buffalo visits Miami next week before the team finishes the season in New England in Week 17. The Patriots could be resting their starters in the regular-season finale so a .500 finish is realistic for a team many experts pegged to finish with the worst record in the league.

For more up-to-the-minute news and analysis on the Miami Dolphins from blogger Dave Carey, follow @CBSDolphins.   

Get more Jaguars updates and analysis from Daniel Lewis @CBSJags.