Alex Smith and the 49ers racked up a franchise-record 621 yards of total offense Sunday in a rout of the Bills. (US Presswire)

Neither Joe Montana, nor Steve Young ever did what San Francisco 49ers QB Alex Smith accomplished on Sunday in a 45-3 rout of the Buffalo Bills (2-3). He led the 49ers offense to more than 600 yards of total offense, while turning in what coach Jim Harbaugh dubbed a “near perfect” performance.

The 49ers (4-1) set a new franchise single-game record with 621 yards of offense, which doubled as the worst defensive performance in Buffalo history. Coincidently, the old records for both teams (598) came when the Bills beat the 49ers 34-31 at Candlestick Park in 1992, which was the only game in NFL history without a punt.

Smith completed 18 of 24 passes for 303 yards and three TDs and set a new career high with 49 yards on three carries.

It’ll be a day remembered for the 49ers’ offensive outburst, but the defense was nearly as good. The unit hasn’t allowed a touchdown over the past two games.

When the game turned: 49ers LB Patrick Willis forced TE Scott Chandler to fumble with 29 seconds left in the first half, and on the next play Smith found WR Michael Crabtree for a 28-yard TD to make it 17-3, 49ers. If the Bills would have been able to get into field goal range, the game would have had a markedly different feel to start the second half.

Highlight moments: Smith had several highlight-reel throws, but his toss on Crabtree’s 28-yard TD was a thing of beauty.

WR Mario Manningham ran one of the more impressive routes in the NFL this year on a double move that left him wide open for a 10-yard TD to make it 31-3.

Top-shelf performances:

  • QB Alex Smith -- 18 of 24, 303 yards, 3 TDs, no INTs, 3 carries, 49 yards rushing

  • WR Michael Crabtree -- 6 catches, 113 yards, 1 TD

  • TE Vernon Davis -- 5 catches, 106 yards

  • RB Frank Gore -- 14 carries, 106 yards, 1 TD

What they said about the 49ers single-game yardage record:

  • 49ers coach Jim Harbaugh -- “I think it means something to the fellas. And they did a heck of a job there, in that throwing and catching and protecting and rushing the football. That was well earned.”

  • 49ers OC Greg Roman -- “It’s a credit to the players and a credit to what we can accomplish as we move along. Yards … (I'm) not a big statistical guy, don’t get caught up in it, but at the same time just over the normal course of events, being able to get that kind of production, obviously we’re doing something right and really think our organization has done a really good job bringing the right kind of guys in here."

  •  49ers QB Alex Smith -- “Crazy. Didn’t know it until the end there when they announced it (over the P.A. system). Very cool. Lot of great offenses. When you think of the 49ers, you think of great offense, so it’s quite an honor to be there with those guys.”

Numbers you should know: The 49ers became the first team in NFL history to rush (311) and pass (310) for more than 300 yards in the same game. … San Francisco had not played a game where it had a 300-yard passer, two 100-yard receivers and a 100-yard rusher in the same game since 1961. … The Bills allowed 500-plus yards of offense in back-to-back games for the first time in franchise history. … The 417-yard differential in yardage marked the biggest margin in Bills history. … San Francisco’s 311 yards rushing was the third-most ever given up by Buffalo.

Injury update: QB Alex Smith sprained the middle finger in his throwing hand on his final play of the game. He was X-rayed following the game and it appears to be a minor injury.

Going forward: The 49ers will entertain the third New York state team in as many weeks next week when they host the Giants in a rematch of the NFC Championship Game from a year ago. “Lot of baggage, lot of history, a little unfinished business, I guess,” Smith said.

The Bills won't return home this week as they look to regroup from a pair of disastrous performances by their defense. Instead, they'll head to Arizona, where they'll practice on the campus of Arizona State in preparation for next week's game against the Cardinals.

Follow 49ers reporter Kyle Bonagura on Twitter @CBS49ers and @KyleBonagura.

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