INDIANAPOLIS - Peyton Manning is adjusting to being without Marvin Harrison. Tony Dungy is finally adjusting to instant replay.

So the Indianapolis Colts are on the verge of their fifth straight AFC South title.

Manning, hampered by a lack of receivers for the last six weeks, threw four touchdown passes, two after the Colts won replay challenges, to beat Jacksonville, 28-25, yesterday and take a two-game lead with four games to go.

It was the second victory by the Colts (10-2) over Jacksonville (8-4) this season, essentially giving them a three-game lead with four games left in a division they have controlled since Tennessee won it the first year of the current configuration.

"I feel great about where we are right now," said Dungy, who during the early years of the challenge system couldn't win any, let alone two, as he did yesterday in a bizarre first quarter that included three challenges.

"Going into the fourth quarter of the season, we've got a good lead in the division and we're second in the conference. If we'd lost, we'd have felt we'd have to win all four of our last games."

Jacksonville's Jack Del Rio all but conceded the title.

"In all likelihood, they'll win the division," said Del Rio, whose team still leads the AFC wild-card race. "They still have to play it out, but they deserve it. We didn't quite get it done today, but I saw a lot of good things."

The Colts' first two TDs came after challenges.

The first one came on the Jaguars' opening possession when Robert Mathis sacked David Garrard and knocked the ball free. Officials first ruled Jacksonville recovered at its 11, but Dungy appealed and referee Terry McAuley ruled the Colts' Raheem Brock recovered.

"I never thought there was a question," Dungy said. "I saw Raheem get the ball. He was down. Then someone knocked into him and knocked it loose."

Two plays later, Manning threw a 5-yard TD pass to Dallas Clark.

On the Colts' next possession, officials ruled Ben Utecht fumbled. Dungy appealed, McAuley ruled it an incomplete pass, and on the next play, Manning threw a 48-yard TD pass to Reggie Wayne, who finished with 8 catches for 158 yards.

Manning, who was 19 of 28 for 288 yards, now has 23 TD passes for the season, tying him with Dan Marino as the only quarterbacks to throw more than 20 in each of their first 10 NFL seasons.

Reggie Nelson's end-zone interception of Manning ended an Indy threat and Josh Scobee's 47-yard field goal cut the Colts' lead to 21-17 early in the fourth quarter. But the Colts scored again on a shovel pass to Luke Lawton.

Antoine Bethea's interception of Garrard, the first against the Jacksonville QB in 231 passes this season, stopped one drive. But he threw a 17-yard TD pass to Dennis Northcutt, then bulled in for a two-point conversion, cutting it to 28-25 with 2 minutes, 47 seconds left.

Indianapolis ran out the clock to win it.