Gurley concedes he's not as fast.
"Oh yeah, I'm 225 (pounds)," the rookie said after setting the tone in a 27-6 victory over the San Francisco 49ers on Sunday. "I can't beat a guy that's 180."
And Austin can't match the durability.
Gurley rushed for 133 yards on 20 carries, topping 100 yards for the fourth straight start to open his career. Austin caught a 66-yard touchdown pass and outran the defense to the pylon for a 2-yard score, compensating for an early lost fumble.
The Rams defense was stout, too, with three sacks and a safety. The St. Louis defense hasn't allowed a touchdown the last two games, permitting just four field goals.
"I could name anybody and everybody on the defense," end Robert Quinn said. "Everyone made some incredible plays."
Gurley, who had a 71-yard touchdown run, is the first rookie to open his career with four consecutive 100-yard games according to STATS with data available since 1991. Gurley's 566 rushing yards are the most in a player's 1st four NFL starts in the Super Bowl era, according to the league.
"I was looking forward to going against him. I've heard so much about him," 49ers linebacker Ahmad Brooks said. "He made some big plays on us today, so hats off to him and his offensive line, but we'll face him again."
The Rams (4-3) are 3-0 against the NFC West for the first time since 2004, and they're above .500 this late in the season for the first time since 2006.
"I expected to be here in years past; things didn't work out," coach Jeff Fisher said. "I'm not satisfied at all, and that has to carry over to the players as well."
The 49ers (2-6) were hit hard by injuries, losing Reggie Bush early to a knee injury, and haven't scored a touchdown in two games. They've lost six of seven, are 0-3 in the division and have lost two straight to St. Louis for the first time since 2004.
"We come to work every single day and we put the hours in," linebacker NaVorro Bowman said. "It's not like we're sitting on our behinds."
San Francisco was short-handed at running back after Bush, starting in place of the injured Carlos Hyde, hurt a knee on a punt return in the first quarter. Bush slipped on concrete near the stands a week after Browns quarterback Josh McCown was shaken up sliding on concrete into a pad in front of the stands.
Coach Jim Tomsula said he didn't see how Bush was injured.
Both teams were whistled for 93 yards in penalties. The 49ers had a very costly call when Ahmad Brooks was called for grabbing Benny Cunningham's facemask, negating Brooks' 41-yard return for touchdown and retaining possession for St. Louis.
Gurley was untouched on his 71-yarder up the middle in the second quarter. Defenders lost ground as he picked up speed for the score that combined with a 2-point pass to Jared Cook made it 10-3.
Austin's 2-yard run with 18 seconds to go in the half put St. Louis up 20-6, a score set up by Cook's 49-yard reception after a pair of 49ers collided trying to make the tackle.
The Rams' 3-0 start against the NFC West is their best since they won seven in a row from Nov. 23, 2003, to Dec. 5, 2004. The franchise hasn't had a winning record since '03 and owner Stan Kroenke wants to move back to Los Angeles.
"St. Louis definitely deserves it and it feels good," Austin said. "I'm glad we can put some wins together, give the people out there something to cheer for."
The last rookie with a starting streak of four straight 100-yarders at any point in the season was Edgerrin James of Indianapolis in 1999.
NOTES: 49ers WR Anquan Boldin (hamstring) was inactive for the first time in three seasons with the 49ers. ... Bush, 49ers backup safety L.J. McCray (right leg), TE Garrett Celek (concussion) and RB Mike Davis (hand) were ruled out at the start of the second half, and P Bradley Pinion (calf) was knocked out in the fourth quarter. ... Austin has a career-best seven touchdowns, one more than he had as a rookie in 2013. ... Rams P Johnny Hekker averaged 49.8 yards in eight attempts and the 49ers had minus-1 yard in returns.