Three-run fourth lifts Pelicans
Davis smacked an RBI single in the first inning and stroked a run-scoring triple in the third. Fisher was hit by a pitch and scored in the third and delivered a two-run single in the fourth to cap the scoring for the Pelicans (27-29).
Jordan Schafer went 2-for-4 for Myrtle Beach, which has won six of its last nine.
Pelicans starter Thomas Hanson (3-2) yielded two unearned runs on three hits while striking out six and walking four over five innings. Sung Ki Jung allowed two hits and fanned two in a scoreless ninth for his 21st save, one behind Kinston's Scott Roehl for the Carolina League lead.
Potomac's Shairon Martis (12-8), who had won his previous four starts, gave up five runs on 10 hits while striking out six and walking two over 5 2/3 frames.
Ian Desmond and Marvin Lowrance both walked and scored on an error in the first for Potomac (28-27). Leonard Davis and Justin Maxwell each had two of the Nationals' seven hits.