The Pacers (14-2) led 5-1 and 7-3 before the Indians (13-5) battled back.
Catawba scored two runs in the eighth and one in the ninth before USC Aiken held on.
Barkell finished 3 for 4 and also scored. JJ Loker was also 3 for 4 with an RBI.
Tyler Stephan (2-0) got the win relief of starter Taylor Peed by pitching two scoreless innings.
Taylor Grover, a former Midland Valley High standout, pitched the final 1⅔ innings to earn his Peach Belt Conference-leading fifth save of the season.