Remsen-Union took the early lead, pulling ahead 16-9 by the end of the first quarter.
"They really out-hustled us and out-scrapped us in the first quarter, and I don't think we were ready for their intensity and their size," Gehlen head coach Marty Kurth said.
"They're big down low and they really took it to us early," he added. "We didn't rebound well. We didn't run the floor well, and they got up and down the floor extremely well."
Then the Jays (2-0) got fired up, scoring 17 points in the second quarter and holding R-U to four, making it 26-20, Gehlen, at halftime.
"We started to get in a rhythm with our offense, and we got some shots to fall," Gehlen girls head coach Kurth said.
Two big threes nailed down the first half for Gehlen, giving them the six-point lead. Junior Hannah Sitzmann nailed one from the arc and senior Emily Holtgrewe sunk another right at the buzzer for the half.
Coming back to the floor after halftime, the Jays made some defensive adjustments to handle R-U's offense.
"The girls really picked it up defensively and did a great job in that second half," Kurth said.
Gehlen scored 15 to the Rockets' eight in the third quarter, giving the Jays the 41-28 lead, and they held the Rockets to four points in the fourth to claim the game.
"We held them to 12 points in the second half," Kurth said.
Gehlen senior Katelin Langel led scoring for the Jays with 15, Hannah Sitzmann logged 13 and Emily Holtgrewe had 11 points.
Juniors Baily Wiltgen and Alison Schnepf both grabbed 11 rebounds.
"They did a great job on the boards for us," Kurth said.
The Jays went 16-for-27 from the free-throw line.
Gehlen heads to Marcus Friday to take on Marcus-Meriden-Cleghorn.