The backups performed as expected, with Collins leading the Titans to a 30-3 victory and Edwards looking mostly like a guy who joined the team three weeks ago.
"Kerry did a nice job, and that's why Kerry's here," Titans coach Jeff Fisher said. "We're very, very fortunate that we have two very good quarterbacks."
Collins completed 11 of 16 passes for 110 yards and a touchdown, directed five consecutive scoring drives and put the Titans (4-2) atop the AFC South. Tennessee, which also got 111 yards rushing and a late score from Chris Johnson, moved into a three-way tie with Indianapolis and Houston.
The Jaguars (3-3), meanwhile, were left in a familiar position. They finished last in the division the past two seasons and are again in chase mode.
"Not the night we were looking for," Jaguars coach Jack Del Rio said. "We turned it over four times, lost our quarterback. ... Not the kind of night we wanted to have."
Young threw a 23-yard touchdown pass to Kenny Britt on the opening drive, then sprained his left knee on the next series.
"He's a little sore," Fisher said, adding that Young also sprained his left ankle. "He could have finished in shotgun."
Collins replaced him and threw a short TD to Bo Scaife, then led the Titans on time-consuming drives to keep control.
"That's part of the life of a backup in the NFL," Collins said.
At 37 years old, Collins has been a starter and a backup. He even replaced Young in the 2008 season opener in Jacksonville, then kept the starting job the rest of the year.
This time, though, he knows his role.
"I'm a short-term fill-in," he said.
Jacksonville was plagued by turnovers for the second straight week. The Jaguars were able to overcome three mistakes against winless Buffalo. No such luck against Tennessee, which has won six of the past eight in the series.
The Titans turned three short fields into 13 points, taking advantage of two interceptions and a short punt. Making matters worse for Jacksonville, tight end Marcedes Lewis fumbled at the Tennessee 10-yard line in the second quarter and receiver Tiquan Underwood let Vincent Fuller rip a pass out of his hands in the end zone in the fourth.
The Jaguars finished with four turnovers.
"We can't shoot ourselves in the foot like that," Lewis said. "It's not them beating us. It's us beating ourselves. It's self-inflicted. And playing from behind, that's not us."
Garrard, hit several times early, completed 7 of 12 passes for 49 yards, with an interception. He sustained a concussion in the second quarter after getting rocked by Will Witherspoon.
"Losing David definitely hurt," Underwood said. "That's our quarterback, our captain, our leader."
Edwards, the former Buffalo starter who was claimed off waivers three weeks ago, stepped in for his first action with the Jaguars. He was 11 of 20 for 115 yards, with two interceptions.
"We never got any offensive rhythm," Lewis said. "To have Dave go out like that, everybody felt they had to press."
The Titans moved the ball with relative ease all night. They finished with 324 yards, including a 35-yard touchdown run by Johnson on his final carry of the night.
Jones-Drew and Johnson set an NFL record the last time they shared a field. Jones-Drew ran for a career-high 177 yards and two touchdowns, Johnson finished with a career-high 228 yards and two scores. Together, they gave the league its first game with at least four TD runs of at least 50 yards.
Tennessee won that one 30-13 last November.
The rematch was nearly as lopsided.
Rob Bironas kicked three field goals, plenty for Tennessee's stifling defense.
The Jaguars only got into Tennessee territory twice. The first one ended shortly before halftime when Lewis caught a short pass from Edwards, turned and let the ball slip out of his hands that the Titans recovered.
Down 20-0 early in the third quarter, Edwards hit Mike Thomas for 21 yards. Cortland Finnegan was called for defensive pass interference and Edwards again found Thomas on third-and-8 from the 18 to get down to the 7. But on third down, Jacob Ford sacked Edwards, and the Jaguars had to settle for a 33-yard field goal by Josh Scobee.
Jones-Drew managed only 57 yards on 17 carries.
All three of Jacksonville's losses have been one-sided affairs. The team has been outscored 96-19 against San Diego, Philadelphia and Tennessee.
"It's unacceptable to lose games in that way," safety Gerald Alexander said. "To have lopsided losses like that, it just shows inconsistency. It's demoralizing."
Jaguars C Brad Meester set a franchise record with his 151st start. ... Jaguars CB Derek Cox (hamstring) missed the game, and the Titans picked on his replacement, David Jones. ... Britt said earlier this week that Jacksonville's pass defense "makes everybody smile, especially the wide receiver room." Young and Collins completed 14 of 21 passes for 171 yards and two touchdowns. ... Witherspoon on knocking out Garrard: "He definitely didn't look good. I saw him wincing on the ground, but that's the nature of the game. It was a clean, solid hit."
After Titans LB Derrick Morgan asked the NFL to research cannabis's benefits on long-term health, Stephania Bell and Field Yates break down why marijuana's current classification would make it difficult for the NFL to study the medicinal benefits.
Brett Favre was one of the quarterbacks Tony Romo admired growing up in Wisconsin and he spoke highly of Favre at his football camp.
Eric Karabell provides a 2016 fantasy outlook for the NFC East, including which players could see their stocks altered most this summer.
JJ Watt pulls Darren Rovell away from his phone and his "business tweeting" for a moment to get a serious workout in and flip some tires.
There are plenty of questions surrounding Oregon State's offensive trio, but with some consistency this group should rank higher by season's end.
Mike McCoy's ranking, Joey Bosa's rookie contract dispute and ranking the NFL's defensive triplets are included in today's notes.