Young talent shone through in the fifth round of Dunedin club tennis on Tuesday night.
Oliver Reid (14) was named player of the day.
He handed experienced Cantabrian Alan de Zwart his first loss for the season.
Reid fought back from a 6-0 first-set loss to take the next two 6-4, 7-6.
However, this was the only success for Mornington-Roslyn Privateers as Eastern Harbour won the other five.
Oliver Scott (19) and Henry Caird (16) unexpectedly pushed their experienced Otago representatives Phil Mirfin and Ken Thomson to three sets before losing.
Young players Conrad Wong, Hee Bum Chung and Matt White took straight-sets wins over more experienced opponents to keep Balmacewen's unbeaten record, with Wong staking a claim for the No 1 Otago spot with a 6-1, 6-3 win over Jeff Elliotte.
Balmacewen went on to beat St Clair 4-2.
When Mornington-Roslyn Raiders beat Taieri 5-1, again it was the young talents who featured, with Matt Foo (19) taking a 6-1, 6-1 win over Phil Williams, and juniors Scott Campbell and Matt Dalziel picking up singles wins.
No 1 Dwayne Cleugh was pushed by Andrew Mitchell before claiming a 7-5, 6-0 result, but Cleugh has struggled for form this season.
St Clair and Eastern Harbour continue to lead the way in the women's competition.
Teenagers were to the fore as Sian English and Lauren Fowler took straight-sets wins for St Clair.
English was particularly impressive in her 6-4, 6-3 win over Brittany Wong.
No 1 for Southland Amy Mulvey and Marlies Marthen (18) won all three for Harbour against Mornington-Roslyn, but had to overcome a match point one down to clinch a 12-10 third-set double tiebreak win
