Martin staked the Honu (11-14) to a quick lead with a two-run shot in the first inning. It was his Hawaii Winter Baseball-best sixth homer and marked the second time this fall he has gone deep in consecutive games.
The 23-year-old infielder/designated hitter has driven in six runs in his last three contests and ranks fourth in HWB with 19 RBIs.
Kyu Hyun Moon of Korea's Lotte Giants had two hits and walked twice and A's prospect Chris Carter scored twice for North Shore, which trails first-place West Oahu by one game in the West Division.
Honu starter Jun Hyeok Heo (1-3) picked up his first fall win, limiting the Sharks (13-12) to one run on four hits over three innings. Tomohisa Nemoto, Brett Hunter (A's) and Dustin Richardson (Red Sox) combined on six innings of two-hit relief.
Sharks starter Josh Stinson (2-2) surrendered four runs on three hits and six walks in 2 2/3 innings. The Mets farmhand struck out one in losing his second straight decision.
Cardinals Minor Leaguer Tony Cruz singled home the lone run for Honolulu, which has lost seven straight to fall one game behind first-place Waikiki in the HWB East.
Daren Smith is an editor for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.