Davis, who had more than 100 yards in each of Carolina's first five games, was held to 10 yards on eight carries in the first half of Sunday's stunning 23-20 overtime victory in Indianapolis. In the third quarter, Davis' right forearm hit the knee of a Colts defender, sending Davis to an X-ray machine in the RCA Dome that trainers couldn't find. So Davis sneaked back onto the field, only to fumble two carries into his return.
NFL beware. Davis might lead the league in rushing heading into Week 5, but the more dangerous runner in Carolina might be the one who replaced him. DeShaun Foster, given up for the NFL knee scrap heap a year ago following microfracture surgery, officially confirmed the Panthers' playoff run by rushing for 85 yards on 16 carries and catching two passes for 54 yards. All in the second half.
"A lot of people are in trouble now," Davis said. "We're a two-headed monster."
After rushing for 20 yards on 10 carries in a first half where they were outscored 13-3, the Panthers overpowered the Colts for 169 rushing yards on 31 carries the rest of the game. Jake Delhomme needed only to make handoffs and watch Colts defenders fall like pins on a bowling alley. The Panthers had 31 running plays compared to only 11 passes after the intermission.
Foster was the story, though. A second-round pick in 2002, Foster looked like the NFL rookie of the year in training camp prior to last season. Redskins defenders couldn't stop him in an opening exhibition game. Then fate slapped the troubled former UCLA star in the knee. He damaged the articular cartilage in left knee and required microfracture surgery, that last-chance option for a 22-year-old knee that was suddenly bone on bone.
Quietly, Foster worked through the pain of his comeback. As training camp approached, the coaching staff and general manager Marty Hurney sensed that the old Foster was returning. The only problem was they had made Davis their main free agent acquisition. Some problem.
"We've known about the two backs, you guys just found out about them today," Fox said to a group of national reporters. "When DeShaun is healthy, he's very good. He's very, very talented. He's big (6-foot, 220 pounds). He's got good hands. He's got great vision."
At halftime, Fox adjusted the run attack from inside traps and counters to more outside runs. Davis loved it. After a Peyton Manning short pass bounced off Marvin Harrison's hands into cornerback Ricky Manning Jr.'s outstreched arms, Davis broke the Panthers first offensive play of the second half for a 28-yard touchdown. That cut the Colts lead to 13-10. On the next possession, Davis had runs of 14, 7 and 3 to set up a 52-yard touchdown pass from Delhomme to Steve Smith.
While trying to make a checkdown block, Davis hit his right forearm on the shin of a Colts player and winced with pain. Fox didn't know Davis had snuck back onto the field following his failed attempt at finding an X-ray machine.
But when Davis fumbled, Fox ordered equipment men to hide his helmet. Foster, used mainly on third downs, was suddenly the running game.
"Coming off last season, I wanted to show I could still play football," Foster said.
Foster had already given a preview of coming attractions in the first quarter when he turned a short screen pass into a 47-yard gain down the right sidelines. Foster displayed power and elusiveness elusiveness, proving that he is almost finished in his comeback from microfracture surgery.
"I'm almost there," Foster said. "I am very close. I would say I'm maybe 98 percent. My speed is almost back, too. If I had all my speed, I would have broken that screen pass for a touchdown."
Dungy is going to regret looking at tapes of Sunday's games because Davis and Foster embarrassed his defenders in this well-played, hard-hitting game.
"They ran outside on us and we didn't tackle well," Dungy said. "We had a chance to get them in the backfield, but they're pretty good backs. They made things happen. Defensively, you've got to be able to stop the run and we didn't do it in the second half."
At 5-0, the Panthers have won road games in Tampa Bay and Indianapolis. They are 4-0 in games decided by six points or less. A year ago, they were 2-4 in four-point games.
"We would have lost this one last year," defensive end Mike Rucker said. "We know what we've got to do. Now, we are winning these games. We're controlling the clock. In the third quarter, we took it away."
All of a sudden, the new powers in the NFC are the unbeaten Vikings and Panthers and they are showing no sign of going away. Here was the Panthers defense playing without defensive tackle Brentson Buckner, who rested a knee.
The Colts entered the game with the fewest three-and-outs on offense in the NFL. The Panthers came out after the half and intercepted a Manning, forced a fumble and had three three-and-out series in a stretch of six possessions. The other series was five plays and a punt.
"Once the momentum changed, it changed their game plan," safety Mike Minter said. "Now, they are on their heels. That was the difference. Now, we got them where they can't throw it down, and if they went to their checkdowns, we'd come up there and hit them."
But Peyton Manning is still Peyton Manning and trailing 20-13 with 3:08 left, he led a nine-play, 91-yard game tying drive capped by a 25-yard touchdown pass to wide receiver Reggie Wayne. Manning was eight for nine for 91 yards on that drive.
"We're a scrappy bunch on defense," Fox said. "Every week, we find things we need to work on, but we've played some very talented teams to date. And you don't shut people out like that."
Rodney Peete, the backup to Delhomme, won the overtime coin toss. Foster had four runs for 26 yards helping set up the 47-yard winning field goal by John Kasay, a comeback story himself with four screws surgically repaired knee. The Panthers are undefeated, and they proved their offense isn't just Stephen Davis.
"I'm very proud of him," Davis said of Foster. "He went in there and did what he had to do. He makes a lot of plays when given the opportunity and he's going to make a lot more."
Meet the Carolina's Two-Headed Monster.
John Clayton is a senior NFL writer for ESPN.com.