Adam Martin opened the scoring for United after fine work from player-boss Chris Milburn.
This sparked Roscoes into life and they roared back thanks to goals from John Price and Lee Sutton.
Tommy Day levelled for Eastfield with a superb solo effort which finished with him rounding the Roscoes keeper and slotting home.
Sutton then missed from the penalty spot and this error was punished as United clinched victory through Luke Kirby from a corner in the last action of the match.
Milburn said: “Our man of the match was Kaylum Stingemore in goal with a great display and a fine penalty save late on.”
Roscoes Bar boss Tom Allen said: “Our man of the match was Liam Rowley, who didn’t stop all game.”
Roscoes are at home to Filey Flyers in the league this Sunday, while Eastfield United are in North Riding FA Sunday Challenge Cup action at Three Fiddlers FC.
Trafalgar powered to a 12-3 win against The Valley at the Flamingo Land Stadium, with hot-shot Billy Logan smashing in six goals for the visitors.
Liam Love also helped himself to a hat-trick and Sam Pickard a brace of goals, with Tom Greenwood also getting on the scoresheet.
Sam Westmorland, Harry Ward and an own goal were the home scorers.
Trafalgar boss Jamie Patterson said: “It was an excellent all-round team performance, so everyone should share the man of match.
Valley manager Ben Kristensen added: “The man of the match award goes to the team as we only had 11 players and I thought the lads grafted hard.
“We went 1-0 up and played well but our heads went and Traf showed their quality.”
Trafalgar are on the road again at Normanby Hall in the NRCFA Sunday Challenge Cup on Sunday morning.
Goal Sports are due to be at home to Angel this Sunday in the league, while Newlands are set to entertain Cayton Corinthians.