For the better part of a decade, the Florida Gators’ formula for victory has involved tenacious defense, good special teams, and just enough offense to get by. For three quarters and change Saturday in The Swamp, coach Jim McElwain’s Gators followed that winning recipe. By the time freshman cornerback CJ Henderson returned his second interception in as many games for a touchdown early in the fourth quarter, Florida’s defense had staked the Gators to a 13-3 lead and limited Tennessee’s potent offense to 191 yards on 55 plays, for an impressive 3.47 yards-per-play average.

Then Malik Davis fumbled a yard from the goal line and what would have been a 19-3 lead, handing the ball back to Tennessee, and the wheels came off. A gassed Gator defense — not helped by an offense that had picked up only five first downs following an opening drive on which UF picked up four — was simply too tired to make the difficult tackles that a hard runner like John Kelly forces. The Vols piled up 204 yards on just 14 plays on their first three three possessions of the fourth quarter, pulling within three points with under five minutes to play.

Then, a Feleipe Franks interception set Tennessee up in Florida territory with four minutes to play, and the Vols quickly advanced to the red zone. But Florida held three times from inside the 10-yard line, and forced Tennessee to settle for a short Aaron Medley field goal.

Florida can take heart in the fact that for all that went wrong for coordinator Randy Shannon’s defense in the fourth quarter, the Gators made the vital stop when they needed to and gave the offense a chance to win. For a young defense learning on the fly, it’s a positive sign and a confidence builder.

“When it came down to it and they were in the red zone and we had to dig our heels in the dirt, you know, make a play and get a stop, we got that accomplished,” sophomore linebacker David Reese said.

Credit: Kim Klement-USA TODAY Sports

Florida’s defense figured to suffer some growing pains this season, having lost five players to the first three rounds of the 2017 NFL Draft in All-SEC linebacker Jarrad Davis, linebacker Alex Anzalone, All-SEC safety Marcus Maye and All-Americans Quincy Wilson and Jalen Tabor. It’s hard to replace that kind of production without a slight stumble, and that was before the season-ending injury to safety Marcell Harris, the team’s best tackler and one of the SEC’s finest near-the-line secondary players.

Florida had five defensive players chosen in the first three rounds of the 2017 NFL draft; only Alabama (six) had more.

The Gators missed Harris sorely Saturday, especially late, when Chauncey Gardner was trying to tackle Kelly in the open field on a lousy ankle. Florida also missed Kylan Johnson’s presence at linebacker; the Texas product is one of Florida’s best tacklers who entered the year with good game experience last season given Anzalone’s tendency to constantly be injured.

When an offense can’t move the football, it’s hard for a defense to play consistently for 60 minutes, and even harder on a humid September afternoon in The Swamp with a defense full of young players who aren’t all entirely used to college pace and speed. But as bad as the fourth quarter was, Florida’s defense was dominant for three quarters, and gained invaluable experience in a tight game.

What’s more, there were some sterling individual performances from young players.

Young defensive linemen Jabari Zuniga, Kyree Campbell and Jachai Polite were all over the Tennessee backfield, combining for 13 tackles, a sack and two tackles for loss and harassing Tennessee’s quarterback Quinten Dormady throughout.

Henderson became the first Gator since all-timer Fred Weary to return an interception for a TD in consecutive games. He also looked more than capable in one-on-one coverage on the afternoon. Marco Wilson made a splendid from-behind tackle on Kelly to save a touchdown and blanketed Tennessee’s star wide receiver Marquez Callaway throughout the game. Wilson had three pass deflections and looked, in effect, a lot like his big brother.

In other words, while what happened to the defense late needs to be cleaned up, Florida put together plenty of quality video for the coaching staff to review this week.

Despite the growing pains, the Gators remain eighth in the country in defensive S & P efficiency, a better measurement of their effectiveness this season than their rather subpar total defense numbers (100th). For perspective, Alabama is No. 1 in S & P defense in the early season, despite a total defense ranking of only 37th. The Gators have also been opportunistic, intercepting five passes and scoring three defensive touchdowns with a very young secondary.

Shannon’s unit will need to put complete games together, of course, starting this Saturday night at Kentucky.

The Wildcats boast veteran QB Stephen Johnson, who limits mistakes and can hurt teams with his legs, as he demonstrated on a 54-yard scramble to seal Kentucky’s victory Saturday at South Carolina. And while Kentucky isn’t terrific up front, tailback Benny Snell Jr. is a workhorse, averaging around 25 carries a ballgame and breaking the 100-yard mark in his last two. Florida has looked vulnerable against the run this season without Harris and Jarrad Davis to clean things up, and will need to be better if they hope to contend in the SEC East.

Nevertheless, the Gators appear to be building confidence in a young defense, and the fact that the unit could do enough against Tennessee to win, despite an offense that spent most the day stuck in the mud, is encouraging for UF.

The next step is to play a complete game.