Baltimore got only four first downs and 65 yards of offense in the first half, yet went to the locker room with a 17-9 lead.
Houston (2-1) led 6-3 before the interception return with 2:39 left in the first half. After a three-and-out by the Texans, Doss eluded several tacklers during his first career punt return for a touchdown.
Give much of the credit to the Ravens defense, which has not allowed a touchdown in eight quarters since a season-opening 49-27 defeat in Denver. With at least a half-dozen new faces, the unit remains a work in progress.
But this was a significant step.
"We do feel we're as far along as we could possibly be with this group," Harbaugh said. "We haven't given up the big plays."
Schaub went 25 for 35 for 194 yards and an interception. He played much of the second half without wide receiver Andre Johnson, who bruised his shin.
"I did not think he could run the way he needs to play, so we took him out," Kubiak said.
Schaub's most lamentable throw was the one that Smith took the other way.
"Poor decision on my part," Schaub said. "You got to be better in that situation, especially late in the half."
Reed long has been part of great defensive performances by the Ravens. This time, he was on the opposite end.
"Baltimore has a great defense," Reed said. "I told the guys coming into this game, defensively they're going to know every move that you're making, everything that you're doing."
Smith, Lewis' replacement at middle linebacker, knew all about Schaub's tendency to look for his tight end in those situations.
"It was something we saw on film during the week," he said. "We got pressure on the play and I jumped the route."
It was his first interception return for a score.
"It's like a dream; it's hazy," he said. "I remember catching it and running as fast as I can."
Copyright 2013 by The Associated Press