SANTA CLARA, Calif. – As Aldon Smith chases down the NFL record for sacks, his specialty becomes of particular significance Sunday night when the San Francisco 49ers face the New England Patriots and the NFL’s top-ranked offense.

The Patriots have been vulnerable most often when opponents put quarterback Tom Brady on his back.

Nobody in the league has been better at that this season than Smith. The NFL leader with 19 1/2 sacks, he enters Sunday’s game three sacks short of the retired New York Giants’ Michael Strahan’s single-season record.

Brady has been sacked seven times in New England’s three losses and only 13 times in the team’s 10 wins. How much pressure Smith and San Francisco’s second-ranked defense can put on Brady could be the key to ending the Patriots’ seven-game winning streak.

But only once during the Pats’ past eight games has Brady been sacked more than once.

“It’s a big challenge to put pressure on Tom Brady when he’s so good with every detail of his game,” 49ers Coach Jim Harbaugh said. “Everything is so refined. There’s not a lot of tips you can get or clues even when he’s in the shotgun.”

Smith has been up for practically every pass-rushing challenge over the past two months, particularly in prime-time games.

He had a career-high 51/2 sacks the last time the 49ers played a night game Nov. 19 against the Chicago Bears. Three weeks before that, Smith had two sacks during a Monday night rout of Arizona. In six career games played in prime time, the second-year pro has produced 12 1/2 sacks.

The spotlight has been shining bright on Smith as he approaches Strahan’s league record set in 2001. Smith is the first player in NFL history to record 14 or more sacks in his first two seasons, and his 33 1/2 are the most ever for a two-year player.

“It’s just that feeling that you get again, being in the spotlight,” Smith said. “Being back under the lights, that’s when everybody got their real love for football. Back in high school under the lights, Friday night lights, you knew it was show time. Everybody just gets up for it.”