Melbourne Victory was edged 1-0 by the Preston Lions, suffering its first loss of the NPL 3 Victoria season on Friday.
Karl Baricevic's first-half goal was all that separated the teams in an even contest at B.T. Connor Reserve.
After collecting four points from the opening two games of the season, the loss marked Victory's first of the campaign.
Victory was forced into some early defending before beginning to build into the contest.
Luca Da Silva fired over from just outside the area following a driving run before Preston opened the scoring.
After Victory cleared a set-piece, Baricevic took a touch before producing a volley from distance to make it 1-0.
Gianluca Iannucci tested Preston goalkeeper Matthew Symes with a 25-yard free-kick just after the half-hour mark in what was an otherwise mostly even first half.
The Lions threatened six minutes into the second half as James Haran headed a corner wide.
Victory was on top to begin the second half, but it struggled to break down the Preston defence.
It created a fine chance in the 74th minute, Iannucci forcing another save from Symes after a pass from Joshua Varga.
Baricevic thought he had found a sealer for Preston following a scramble in the area, but it was ruled out after a foul on Victory goalkeeper Christian Siciliano.
Victory pushed late but was unable to find an equaliser as it fell to defeat.
General Manager – Football Drew Sherman's post-match thoughts
"Naturally it's disappointing to suffer our first defeat, particularly in a match where we felt we were truly in the contest throughout. On the balance of play I felt we deserved a point from the game this evening.
"Although we walk away tonight empty handed, I think our players to a man, can be really proud with the performances that they put in. In my opinion defensively we were astute, it's a wonderful strike that separates the teams; but other than that I don't really recall Siciliano making a save of note or even them getting in behind our back line very often.
"Having said that, although we had a lot of the ball and played some nice football in our build-up moments, it's probably fair to say that we lacked a little cutting edge in the final third tonight too. It's certainly something we will be looking to work on and need to improve if we're to have a successful season.
"Credit to Preston Lions, they were well organised and made it hard for us, physically they made tonight a battle and our boys have to learn to protect themselves a little better playing senior football. I can't see many teams coming and taking points from them here if they play and compete like that week in, week out."
NPL 3 Victoria 2021 Round 3
Preston Lions 1 (Karl Baricevic 28')
Melbourne Victory U21s 0
Melbourne Victory: Christian Siciliano (gk); Edmond Lupancu, Matthew Bozinovski (c), Aisen Ishak, Thomas Lambiris; William Wilson, Luca Da Silva (Jack Morton), Joshua Varga (Marc Latsis); Nishan Velupillay, Ryan Lethlean (Adem Duratovic), Gianluca Iannucci.
Victory's U19s will face the Preston Lions at B.T. Connor Reserve on Sunday.