The Northern Ireland international hit a treble in the recent 7-2 win over Waterford at the Brandywell, and he repeated the trick here in this 5-1 victory, coming off the bench in the second half with the score at 0-0 to make all the difference.
Tiernan Lynch gave a debut to striker Dipo Akinyemi at Markets Field, while he also handed a first start to Alex Bannon.
Meanwhile, Adam O’Reilly made his first start in five games as the Candystripes began what they hoped would be the first step on the road to a third FAI Cup Final in four seasons.
City started with intent and Bannon had a good chance to break the deadlock on five minutes, but the unmarked centre-back was unable to keep his header down after Michael Duffy’s right-wing corner had picked him out at the back post.
Derry City’s new signing Dipo Akinyemi in action during his side’s FAI Cup victory over Treaty United
City then had the best chance of the game four minutes before the break when Duffy’s clever pass threaded through the Treaty defence, right into the path of O’Reilly who was denied only his third Derry City goal by Corey Chambers, who produced a strong stop from close range.
Lynch strengthened his attack early in the second-half with the introduction of Boyce from the substitutes’ bench, and it proved to be immediately effective as the striker rose to meet Duffy’s corner to send a looping header over Chambers and into the top corner to make it 1-0.
Derry City then doubled their lead on 71 minutes as Treaty got caught from a corner again, this time Duffy’s delivery met with a header from Bannon, who celebrated a goal on his first start for the club.
Treaty United were simply unable to contain Derry City from corners as the visitors scored a third just three minutes later, Boyce again on hand to direct a header over Chambers and into the net, in doing so hitting double figures for the 2025 season.
Derry City boss Tiernan Lynch congratulates goalkeeper Brian Maher following his side’s victory over Treaty United
Treaty did pull a goal back 11 minutes from time when Brin Cunningham’s mishit shot fell perfectly for Lee Devitt, who calmly placed the ball beyond Brian Maher.
The game was over as a contest with six minutes remaining, however, as Derry scored again with Boyce completing his second hat-trick in three games.
The striker was brought down by Chambers, giving referee Lucas Keating an easy decision, and Boyce hammered the ball confidently past the Treaty goalkeeper.
Derry were showing no mercy late on as they added a late fifth, Adam Frizzell setting up Danny Mullen to score to give the scoreline an emphatic look.
Treaty United: Chambers, O’Connor, Walsh, R Lynch, B Lynch, Conroy (Byrne 77), Healy (Doherty 89), Wilson (Cunningham 65), Devitt, Murphy, Vrljicak (Ferry 77).
Derry City: Maher, R Boyce (Benson 77), Bannon, Connolly, Todd, Ferguson (Cann 56), O’Reilly, Diallo, Whyte (L Boyce 56), Duffy (Frizzell 77), Akinyemi (Mullen 69).
Referee: Lucas Keating
Man of the Match: Liam Boyce (Derry City)
Match rating: 7/10