It came a day after the Royals swept the Islanders in Charlottetown.
The Islanders won 7-4 and 13-9 after losing 4-2 and 5-4.
Jordan Stevenson won the opener Sunday while Taylor Larkin picked up the win in Game 2. No further details were available from Sunday’s games.
The Islanders (6-14) head to Moncton on Wednesday to play the Fisher Cats at 7:30 p.m. before hosting Saint John for a doubleheader on Saturday beginning at 2 p.m.
The Royals won Saturday’s opener 4-2 after leading 1-0 after the first inning and 2-0 after four.
Charlottetown tied it in the bottom of the sixth, but Fredericton responded with two in the top of the seventh.
Shane Kraemer allowed two runs on four hits and three walks for the win. He struck out 12.
Larkin allowed two runs on three hits and a walk in the seventh inning. Starter Brady Arsenault allowed two runs on five hits and five walks in six innings.
Dave Barr was 3-for-4 with two runs scored for Fredericton while Jay Johnson was 1-for-4 with two stolen bases and two RBI.
Jesse MacIntyre, Jordan Duffy, Brody McDonald and Jeremy McKinnon had the Isles hits while MacIntyre also walked twice. Stevenson and Josh McKinnon had the RBI.
In Game 2, Fredericton led 4-3 after one inning and added a run in the third. Charlottetown scored in the fifth.
Johnson allowed four runs on four hits and seven walks in six innings for the win. He struck out eight.
McDonald was tagged with the loss after giving up five runs on eight hits and two walks in five innings. He struck out three.
Shawn Reid had three of the Royals nine hits while Mike Washburn drove in two runs.
Stevenson hit a home run and drove in two runs for the home side while MacIntyre, Grant Grady and McKinnon also had hits and Grady had an RBI.