Jason Allen didn't just separate Hines Ward from the football on a crucial third-down play against the Steelers last week. He may have separated the Houston Texans from the long-running Kareem Jackson nightmare.

Allen's taken Jackson's starting job — the one Texans' fans often wondered how the first-round draft pick draft held onto. For the second straight week, Allen started in place of Jackson Sunday and this time Jackson was healthy and active for the game. Making what Texans coach Gary Kubiak called the biggest play of the game, in a game that Texans owner Bob McNair painted in terms of being the biggest in franchise history, can do that for you.

In truth though, it wasn't just Allen's man-from-ball parting hit on third down and his interception to end the Steelers' last chance that vaulted him over Jackson on the depth chart. Allen played Jackson to a virtual standstill throughout the preseason and easily could have won the starting job then.

Not that the former wavier claim (the Dolphins cut Allen last season) is celebrating.

"We're a family back there in the secondary," Allen told CultureMap after the Steelers game. "When I'm in there, Kareem's pulling for me and when Kareem's in there, I'm pulling for him. And a lot of times we'll be out there together. We only wish the best for each other.

"We're a unit. It's about what we do as a defense. That's what counts."

Still, not having Jackson starting in Wade Phillips' revamped defense carries some symbolic value for a unit that's crafting a new identity.

Jackson may not have had one of the worst rookie seasons in NFL history. That's probably a little much.

But it sure felt that way to Texans' fans.

Seeing No. 25 get beat, burned and blistered in every way possible served as one of the enduring images of a 6-10 nightmare. Now, he won't be back there quite as much. That doesn't mean that the Texans will not get burned. Allen was beat badly on a flea flicker play early in the first quarter Sunday. But Raiders quarterback Jason Campbell overthrew the wide-open receiver by 10 yards.

Maybe, Houston's luck is changing.

For once Oakland pulled within 7-6 in the second quarter, despite no semblance of offense whatsoever, Allen picked off a long Campbell pass for Jacoby Ford, completely flipping the game's momentum. The Texans scored on their very next play — a 56-yard touchdown pass to a wide-open Joel Dreessen — to go up 14-6.

"Jason's a fighter," said Johnathan Joseph, the Texans' $50 million free-agent cornerback, a talent that changes a lot. "He's going to compete. He's been doing that since the first day of training camp."