MIAMI, Fla. — In three miserable days in Miami, Southern Miss went from the top of the mountain in Conference USA to the middle of the pack.

Nick Day hit two of Florida International’s four home runs Saturday as the Panthers beat Southern Miss 13-8 to complete a three-game sweep.

Southern Miss has now lost four consecutive games — the first time it’s lost more than two in a row all season — heading into the Conference USA Tournament in Hattiesburg. The Golden Eagles (36-18, 20-10 C-USA) started the weekend in first place in the league, but wound up finishing third behind Florida Atlantic and Marshall. USM will open the C-USA Tournament Wednesday at 4 p.m. against Old Dominion.

Florida Atlantic beat Western Kentucky 4-1 on Saturday. That, combined with Marshall’s 4-3 loss to Old Dominion, gave FAU its first Conference USA regular-season championship.

Southern Miss, trying to salvage the series and its fading title hopes, got off to a great start Saturday. Daniel Keating singled in two runs as the Golden Eagles scored four times in the top of the first inning. They added another run in the third to go up 5-1, and then things started to unravel.

Day clubbed a two-run home run in the bottom of the third, and in the fourth inning Eddie Silva hit a three-run homer to put the Panthers ahead 7-5. Day added his second two-run homer later in the fourth inning.

Florida International (28-27, 15-15) sent 10 men to the plate and scored six times in the fourth inning, and never trailed again.

Kenny Meimerstorf hit the team’s fourth home run, a two-run shot in the fifth inning, as FIU tacked on four more runs to go up 13-5.

Day finished 2-for-4 with four RBIs and two runs scored, while Silva drove in three runs and scored two for Florida International. Catcher Nick Mira went 3-for-4 with an RBI and three runs scored.

Tim Lynch hit his ninth home run of the season for Southern Miss and finished 2-for-4 with two RBIs. Hunter Slater was 3-for-4 with two doubles and three runs scored, and Keating drove in a pair of runs.

Southern Miss starter Walker Powell, who had pitched well in his previous two starts, failed to make it out of the fourth inning this time around.

Powell (4-3) allowed seven runs — only three of them earned — on six hits in 3 2/3 innings. He walked one batter and struck out four.

Conference USA Tournament

At Hattiesburg

Wednesday, May 25

Game 1 – Louisiana Tech vs. Rice, 9 a.m.

Game 2 – Charlotte vs. Florida Atlantic, 12:30 p.m.

Game 3 – Old Dominion vs. Southern Miss, 4 p.m.

Game 4 – Florida International vs. Marshall, 7:30 p.m.

Thursday, May 26

Game 5 – La. Tech-Rice loser vs. Charlotte-FAU loser, 9 a.m.

Game 6 – Old Dominion-USM loser vs. FIU-Marshall loser, 12:30 p.m.

Game 7 – La. Tech-Rice winner vs. Charlotte-FAU winner, 4 p.m.

Game 8 – Old Dominion-USM winner vs. FIU-Marshall winner, 7:30 p.m.

Friday, May 27

Game 9 – Game 5 winner vs. Game 7 loser, 3 p.m.

Game 10 – Game 6 winner vs. Game 8 winner, 6:30 p.m.

Saturday, May 28

x-If necessary

Game 11 – Game 7 winner vs. Game 9 winner, 9 a.m.

Game 12 – Game 8 winner vs. Game 10 winner, 12:30 p.m.

x-Game 13 – Game 7 winner vs. Game 9 winner, 4 p.m.

x-Game 14 – Game 8 winner vs. Game 10 winner, 7:30 p.m.

Sunday, May 29

Championship game, 1 p.m.