The Doncaster club burst out of the blocks and lead 51-47 at the half-way stage.
Eagles, however, were forced to travel with eight players due to injuries and work commitments. And it caught up with them as unbeaten Newcastle finished the game on top.
“We played well for three quarters but as in most of the games this season depth proved a major problem,” said head coach Bob Martin.
Josh Metcalf (22), Mathew Martin (20) and Liam Knapp (18) led the scoring for Eagles.