The Newcastle Jets have proven their own worst enemies in a 2-0 loss to Melbourne City at McDonald Jones Stadium on Sunday afternoon.
Two soft turnovers and a lack of polish with their own chances proved telling in the round-six clash.
City took a 1-0 lead in the 11th minute after a wayward back pass from Thomas Aquilina put Phillip Cancar under unnecessary pressure deep in his own territory.
The Jets centre-back managed to play the ball forward to Dane Ingham, but the New Zealand international gave up the ball cheaply and Marin Jakolis quickly whipped a cross into the box to find 18-year-old Benjamin Mazzeo lurking and unmarked to head home in his A-League starting debut.
The second goal, scored by Jamie Maclaren, came in similar fashion in the 58th minute after Cancar was dispossessed by Jakolis.
Jakolis drove at the Jets' defence before playing inside to Tolgay Arslan, whose quick no-look pass at the top of the 18-yard box had Maclaren unmarked and shooting from close range.
In his A-League debut, 19-year-old striker Justin Vidic produced plenty of good moments in a 60-minute effort for Newcastle.
His blistering left-footed strike in the 25th minute was parried over the byline by diving City shot-stopper Jamie Young and was arguably the host's best clear-cut chance.
Vidic was signed by the Jets on a scholarship deal after an impressive NPL NSW season with Marconi.
He took the place of Newcastle's leading scorer Apostolos Stamatelopoulos, who was unable to train on Saturday due to a hamstring issue.
Trent Buhagiar hit the crossbar with a long-range strike in the 33rd minute and Clayton Taylor put a shot across the face of goal in the 36th for Newcastle.
In the other change to Newcastle's starting XI from their 3-1 loss to Central Coast in round five, fullback Aquilina made his first start of 2023-24. He replaced wide midfielder Lachlan Bayliss, who was left out of the squad.
In a positive showing, attacking sparkplug Reno Piscopo was named on the bench after missing the opening five rounds due to a calf complaint and was deployed into action in the 60th minute.
Home-grown teenage talent Archie Goodwin, who scored off the bench against the Mariners in his first appearance this season, also took the field for the second successive outing.
Goodwin was controversially pulled down by Young near the sideline as he went on the attack in the 78th minute but the City goalkeeper only issued a yellow card for the hands-on challenge.
The Jets, who remain on five points after six games, next face unbeaten competition pace-setters Wellington in Wellington on Saturday.
Newcastle's A-League Women's side had the weekend off due to an international window. They are set to host Sydney FC at No.2 Sportsground next Sunday.