The Golden Eagles, who swept Houston by scores of 10-9, 13-4 and 8-5, improved to 21-17 overall and 5-7 in conference play.
Before the sweep, the Golden Eagles were in last place and on the verge of missing the C-USA Tournament, which is set for May 26-29 in Houston. Only the top six teams qualify for the tournament.
Southern Miss is now tied with Alabama-Birmingham for sixth place with a key weekend series at Tulane (25-16, 6-6) ahead. USM hosts South Alabama today at 6:30 p.m. in non-conference action.
"It was good to get the sweep," Southern Miss coach Scott Berry said. "We played loose and that was the key. I also think we had a little of our swagger back.
"This was the first time that I've seen that swagger since we played at (Louisiana) Lafayette (on March 19-21). This puts us tied for sixth, but we still have a lot of work left to do (with 15 games left). It was a good weekend for us, especially at the plate. We played with confidence, too."
Southern Miss won its first C-USA series dating back to last April at Houston.
"We lost the last five conference series last year," Berry said. "Then we lost the first three this year. We needed this.
"In the three (series) we lost this year, it was all about missed opportunities. I hope we learn from that and move forward."
Southern Miss hit .385 for the weekend with six home runs and 30 RBIs. Senior second baseman Taylor Walker hit .467 while sophomore shortstop B.A. Vollmuth of Biloxi hit .462.
For the season, the Golden Eagles are hitting .317 with 46 home runs and 294 RBIs.
"I thought we hit the ball well," Berry said. "I would like to see Ryan McNamara (the Sunday starter) going deeper into the game. But I thought we pitched better against Houston. Now we need to carry the momentum to Tulane."
The sweep also pushed Southern Miss' RPI to No. 85 with South Alabama at 57 and Tulane at 68.