Brown ran for 180 yards - the most for Georgia in six years - and scored three touchdowns and No. 15 Georgia beat Mississippi 45-17 on Saturday.
Led by Brown, Georgia (4-1, 2-1 Southeastern Conference) scored the final 28 points.
``It was just a beautiful, beautiful job of running,'' Richt said. ``He finally broke out in space and had some big runs.''
Four of Georgia's five rushing touchdowns came after the Rebels opened the second half with an 18-play, 84-yard touchdown drive for a 17-17 tie.
``That's one of the biggest margins of victory in a game I've coached that was really close,'' Richt said. ``We got outplayed in the first half.''
The Rebels hurt themselves with two turnovers, including a first-quarter fumble by quarterback Seth Adams on a first down at the Georgia 1 when they were trying to take a 14-0 lead.
``The fumble really hurt us down there,'' said Ole Miss coach Ed Orgeron. ``All I saw was the ball on the ground. It was a really big play. ... In hindsight I should have called a timeout to have it reviewed.''
BenJarvus Green-Ellis ran for 108 yards and a touchdown for Ole Miss (1-4 overall, 0-3 SEC).
Brown had scoring runs of 50, 4 and 41 yards. He averaged 11.2 yards on 16 carries.
Moreno was Georgia's leading rusher through four games, and he added 90 yards rushing with a fourth-quarter touchdown against Ole Miss.
``I don't think anyone on the team really cares who starts,'' quarterback Matthew Stafford said. ``They get about the same amount of touches. It's awesome to watch them.''
Georgia rushed for 328 yards, the first time the Bulldogs ran for 300 yards in seven years under Richt and the team high since it compiled the same total against Vanderbilt in 1991.
Brown took over following the long Ole Miss tying touchdown drive. He had four carries and one catch for 45 yards on a seven-play touchdown drive that ended with his 4-yard run. He added a 41-yard touchdown run early in the fourth quarter.
Brown's rushing total was the high for Georgia since 2001, when Verron Haynes ran for 207 yards against Georgia Tech. Brown matched his career high with the three touchdown runs.
Georgia only led 17-10 at halftime. Ole Miss tied the game with an 18-play drive that lasted more than 9 minutes to open the second half.
The Rebels led 7-0 following a 45-yard touchdown pass from Adams to Mike Wallace.
Adams was 24-of-35 passing for 228 yards with one touchdown and one interception - and one crucial fumble.
``By all rights we should have been down 14-0 and then you don't know what's going to happen,'' Richt said.
Said Adams: ``Those turnovers really killed us. They didn't beat us, we beat ourselves. They have a good team, but we didn't play well in the second half. We just got completely outplayed.''
C.J. Byrd recovered Adams' fumble at the 4, and Georgia drove 96 yards for the tying score. The drive appeared to have stalled at midfield when Georgia faced a third-and-19 play.
With Ole Miss expecting a pass, Brown took a handoff on a draw play and, with the help of a downfield block by right guard Clint Boling, ran 50 yards for the touchdown.
After showing his power on the 50-yard run, Brown used a fancy juke on Ole Miss safety Kendrick Lewis to cap his 41-yard scoring run.
``I like to run people over, but I ran people over earlier,'' Brown said. ``This time I gave 'em something different.''
Brown has made a strong return from a knee injury midway through the 2006 season.
``It's good to see a guy like Thomas, all he's been through, come out and have a breakout game,'' said Georgia center Fernando Velasco. ``That's what we needed.''
Richt said he stuck with Brown as the starter when Moreno was the team's leading rusher because ``You want your leader as your starter.''
Following the only Ole Miss punt of the half, Georgia drove 80 yards in 13 plays. Stafford threw a 5-yard scoring pass to Mohamed Massaquoi. Stafford was 13-of-21 passing for 144 yards and a touchdown.
Georgia linebacker Brandon Miller's interception set up Moreno's fourth-quarter touchdown for a 38-17 lead and freshman fullback Fred Munzenmaier added a 6-yard touchdown run in the final minute.