That play, however, demonstrated the secondary's inability to make plays throughout the afternoon.
Yes, the Dolphins came up with two interceptions in the game after recording only one in the first four games, but they couldn't cover Johnson or the middle of the field.
Another big play in the Texans' final drive came when wideout Kevin Walter inexplicably was left wide open in the middle of the field for a 30-yard completion to the Miami 30-yard line.
The late touchdown came after Ronnie Brown had scored on a 6-yard run with 1:45 left to give the Dolphins a 28-23 lead.
The score came on a second-and-4 from the 6 with Houston having only two timeouts left, so in essence Brown might have done the Texans a favor by scoring so quickly.
Still, Houston's final drive began well for the Dolphins, with Joey Porter sacking Schaub for a 6-yard loss on first down.
But then the Dolphins allowed a 20-yard completion to Andre Davis, followed by three straight incompletions. Then came the fourth-down completion to Johnson.
Early on, it didn't look like the game was going to come down to the wire. The Dolphins used two big plays, both to Patrick Cobbs, to take a quick 14-3 lead.
Cobbs later took a screen pass and turned it into an 80-yard touchdown and the Dolphins seemed to be on a roll.
But the special teams problems that have haunted the Dolphins all year surfaced again, this time in the form of a 70-yard punt return for a touchdown by Jacoby Jones.
From there, it became a back-and-forth game until the end.
It was the Dolphins' third loss at Reliant Stadium in the last three year, following a two-point loss in 2006 after the Dolphins failed on a late two-point conversion and a three-point loss last year on Kris Brown's 57-yard field goal on the last play.
For good measure, Houston also took the teams' first meeting in 2003, winning by two on a last-second field goal.