HATTIESBURG, Miss. (AP) -- Southern Mississippi coach Jeff Bower wasn't totally satisfied by his team's performance despite a shutout that positions them well in Conference USA.

While praising his defense after the 24-0 win Saturday over Army, Bower said the scoring gap could have been bigger.

Southern Mississippi (Unranked ESPN/USA Today, No. 25 AP) had two turnovers and blew several opportunities.

"I think that if our offense would have been sharper we could have put up more points in the game with the great field position we had," he said.

Derrick Nix ran for two touchdowns and Southern Miss held Army to 202 yards of offense.

Nix had scores in each of the first two quarters, and the Golden Eagles capitalized on Army miscues in the visiting team's first ever game in Mississippi.

Kelby Nance scored Southern Miss' other touchdown on a 2-yard run midway through the fourth quarter.

Southern Mississippi (4-2, 3-0 in Conference USA) amassed 351 yards of offense. But it was the defense Bower was pleased with.

"I believe in this defense. When they get ready and tee it up, they're good," he said.

The only serious Army (2-4, 1-3) threat came on a fake punt in the second quarter. Punter Graham White lumbered for 35 yards past a surprised Golden Eagle defense. Three plays later, Matt Parker's field goal attempt was far short.

Army had three fumbles and one interception, but none led to Southern Mississippi scores. USM's Brant Hanna missed one field goal attempt set up by a Michael Wallace fumble. Hanna booted a 21-yard field goal in the third quarter.

Nix, who rushed for 85 yards on 21 carries, scored from 4 yards out in the first quarter and had a 1-yard TD in the second period.

His second touchdown was set up by a short Army punt, a 21-yarder, that gave the Golden Eagles good field position with 2:06 left in the first half. Quarterback Jeff Kelly connected on passes of 21 and 9 yards on the drive and sprinted another 9 yards through an opening to the Army 1-yard line to set up the Nix score.

Kelly was 17-of-31 for 195 yards. He threw one interception, in the third quarter, which ended a 67-yard drive. Kelly's favorite target was Sherrod Gideon, who caught five passes for 82 yards. The longest was 32 yards.

Nance, a third-string player, had a TD on his only carry of the game. Southern Mississippi was playing at home for the first time in over a month after three road games against ranked teams.

Army, which had 480 rushing yards a week earlier against Louisville, had just 30 yards in the air and 172 on the ground. Wallace had 49 yards, the most of any rusher. Quarterback Chad Jenkins was 2-of-5 for 30 yards. Also sharing time was Joe Gerena, who threw one interception and fumbled the ball away once.

Army coach Bob Sutton said Southern Mississippi's defense kept his team off balance.

"We couldn't crack them," he said. "They're very good on defense because they are talented, mobile and they play with tenacity."

Sutton said his defense "kept us in the game," but mistakes kept the team out of the end zone.

Army was 4-of-16 on third down conversions, while Southern Miss was 5-of-14.

Southern Mississippi has had one shutout in each of its last four seasons.