The 16-year-old opened the scoring on 32 minutes before completing the win in the 89th-minute. The teenager also tallied two assists in last weeks 3-2 defeat by Portugal to take the number of goal contributions to four in two matches.
Lacey is being touted as one to watch in the academy having made his Under-18s debut aged just 15 last season, with the right-winger going on to score three times and notch two assists in 13 games.
He played 11 times for Englands Under-16s last term, recording two goals and two assists in all. Lacey has now continued his rise through the age groups and started for the under-17s for the first time against Portugal.
Meanwhile, fellow United youngster Jayce Fitzgerald got onto the pitch against Spain for the final seven minutes having started the loss to Portugal. Elsewhere, Maxi Oyedele provided the assist for the only goal in Poland Under-21s 1-0 victory over Estonia after making his debut versus Kosovo last week.
Lacey penned a new scholarship agreement in August with a view to signing his first professional contract when he turns 17 amid significant interest from clubs around Europe. Erik ten Hag has already held in-person meetings with several United academy stars, including Lacey.
The United boss has decided to have more of a direct responsibility to bridge the gap between youth system and first team having felt the Under-21s were isolated upon his arrival.
A plethora of youngsters have joined the first-team for training during his tenure and he has overseen the likes of Alejandro Garnacho, Facundo Pellistri and Kobbie Mainoo taking the next step into senior football.