SAN FRANCISCO -- The 49ers' Tramaine Brock instantly extended Matt Schaub's historic streak to four consecutive games of having a pass intercepted and returned for a touchdown.

On Schaub's first pass attempt for the Texans, Brock broke off covering Keshawn Martin, picked off the pass intended for Andre Johnson and returned that theft 18 yards for a 7-0 lead only 1 ½ minutes into Sunday night's game.

It was the first interception this season by a 49ers cornerback. Brock was in the No. 3 role for a second straight game in place of Nnamdi Asomugha, who was sidelined again with a hyperextended knee.

That streak of four straight games with an interception-return for a touchdown is the longest in NFL history.

Last Sunday, Schaub had a pass intercepted and returned for a game-tying touchdown by Richard Sherman in the Seattle Seahawks' overtime win in Houston.

Schaub rebounded from Brock's pick-six by completing 5-of-6 pass on the Texans' next drive, which ended with a failed attempt at a 45-yard field-goal attempt.

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