The Welsh youngsters produced their finest performance of the European Championship qualifiers, and were unfortunate to fall to a single goal defeat against a more experienced and physically stronger Ukraine side at the Dynamo Kiev stadium.
In extreme weather conditions, and only pride to play for, the Welsh showed signs of a brighter future ahead. Hillier played at right full-back, turning in a performance that will surprise no-one at White Hart Lane.
The cruel, yet decisive moment came after 58 minutes when Stephan Molokutsko raced clear on the right and was brought down by Swansea's young keeper Jason Jones inside the penalty area. Molokutsko regained his poise to drive home the penalty.
The setback did not dim the pride of manager Jimmy Shoulder, who beamed: "I was enormously encouraged by what is easily our best performance of the tournament.
"Ukraine are a very, very good side who overpowered us in March at Swansea. But I felt sorry for my lads for coming away with nothing. We deserved so much more.
"We had the application, made fewer mistakes than normal and considering the conditions we were outstanding.
"People feared the worst beforehand, considering our previous results, they were wondering just how many we would concede. But the spirit and effort was magnificent and we stood up to be counted.
"I can't be prouder of such a young bunch of lads who made the best team we have played by far struggle all game."
Meanwhile, Northern Ireland under-21s, containing young Spur Ciaran Toner, fell to a 4-0 defeat against the Czech Republic. A busy few days for Ciaran will culminate in the young midfielder taking his place on the bench for the senior side on Wednesday afternoon.
Ian Hillier starred for Wales under-21s, but could not prevent them falling to a seventh defeat in a row.