Saint Louis junior outfielder Cole Smith smacked two hits Friday afternoon, but the Billikens fell 11-4 to Marshall at Hoover Metropolitan Complex in Hoover, Ala.
SLU moved to 0-1 on the season, while the Thundering Herd went to 1-0.
Marshall jumped out to a 7-0 lead after scoring six runs in the second inning and tacking on another in the third.
Smith drove in Ethan Sitzman with an RBI single to right field in the bottom half of the third inning.
The Herd increased its lead to 10-1 with a three-run fourth inning.
An Austin Neuweg RBI double and a Sitzman sacrifice fly scored two for the Billikens in the sixth inning, and a Cody Jansen RBI single made it 10-4 in the seventh.
Marshall added one more run on a solo home run in the eighth frame.
Henry Litman tossed 3.2 innings of scoreless relief, striking out four and scattering just five hits.
The Billikens return to the diamond Saturday afternoon at 2 p.m. for game No. 2 against Marshall.