LAS VEGAS -- Matt Austin withdrew from the National Finals Rodeo on Sunday, giving up a shot at a second straight world bull riding title because of injuries that made it impossible to compete.

Austin, from Wills Point, Texas, tore abdominal and groin muscles during a ride in Liberty, Texas, in October. He had a successful ride Thursday, then was bucked off his second-round bull Friday and had to be helped from the arena.

Austin's departure put NFR aggregate leader B.J. Schumacher of Hillsboro, Wis., in good position in the world standings, which Austin leads with $157,716. Schumacher, who was bucked off Sunday in the fourth round, was second with $150,142.

Wesley Silcox of Payson, Utah, moved into third place in the world standings with $134,598, winning the fourth round with a 90.5 on Golden Ghost. Silcox and J.C. Bean of Goldendale, Wash., who had an 85.5, were the round's only successful riders.

In bareback riding, defending world champion and world standings leader Will Lowe of Canyon, Texas, placed first on Parlor Game with 84.5 points for his second consecutive win. Lowe increased his world lead to just over $65,000 over Andy Martinez of Pavillion, Wyo., who placed sixth with an 81 on a re-ride.

"I feel good and feel like the week's going good so far,'' Lowe said. "But you just take it one at a time. We've got the fifth round tomorrow, and we're not even halfway through this son-of-a-gun yet. There's a lot of rodeo left.''

Cody DeMoss of Heflin, La., was second in saddle bronc with an 85.5 for the second consecutive round, and it helped him maintain his world lead over Chad Ferley of Oelrichs, S.D. Ferley won the round with an 86 on Sams Town.

In tie-down roping, world standings leader Cody Ohl of Hico, Texas; Cade Swor of Winnie, Texas; and Jerome Schneeberger of Ponce City, Okla., ended up in a three-way tie for first with times of 7.4. Ohl, a five-time world champ, increased his world lead over Trevor Brazile of Decatur, Texas, to just over $55,000.

In steer wrestling, Stockton Graves of Newkirk, Okla., took first in a time of 3.3 seconds. Joey Bell Jr. of Malakoff, Texas, was second in 3.4 and Dean Gorsuch of Gering, Neb., came in third in 3.7. Gorsuch took over the world lead from Luke Branquinho of Los Alamos, Calif., who was fourth in 4.1. Gorsuch has earned $124,496, just ahead of Branquinho at $122,165.

In team roping, Jay and Randon Adams, both of Logandale, Nev., won with a 4.2. Speed Williams of De Leon, Texas, and Clay O'Brien Cooper of Morgan Mill, Texas, followed in 4.3. The runner-up finish allowed header Williams ($102,170) to take over first place in the header world standings from Matt Sherwood of Queen Creek, Ariz. ($99,793).

Brandie Halls of Carpenter, Wyo., won the barrel racing in a time of 13.77 on Slim. Tana Poppino of Big Cabin, Okla., claimed second in 13.94 while Kelly Maben of Spur, Texas, came in third in 13.96.

In all-around, Trevor Brazile of Decatur, Texas, continues to lead by over $100,000 in total winnings. Brazile has earned $299,948, while Beaver is second with $183,309 after four rounds.