Coagh secured an Irish Cup quarter-final clash with holders Linfield after a comfortable replay win at Hagan Park.
Steven Park's low drive put the Championship Two leaders ahead but Ricky-Lee Dougherty curled into the top corner to level for Newbuildings.
Jason Gillespie restored Coagh's advantage with a back-post header.
Steven Wallace's own goal made it 3-1 and Gillespie netted a penalty before Newbuildings defender Graham Moore was red-carded for dissent in injury-time.
Gillespie's pass set up Park for the 14th minute opener but Dougherty equalised for the Intermediate League visitors within 60 seconds from Paul McIvor's cross.
Newbuildings left Gillespie unmarked from a corner as Coagh moved back in front four minutes before the break.
Aaron Campbell's shot deflected off Wallace and into the net on 67 minutes and Gillespie made it four from the spot with seven minutes left after Glen Clarke was fouled by keeper Connor Thornton.
Moore was dismissed for dissent two minutes into added time to complete a miserable afternoon for Newbuildings.
Coagh will take on the Blues at Windsor Park on Saturday, 3 March.