Jono Viviani scored after 36 minutes to reduce the deficit before Casas scored his second goal of the match and 10th of the season four minutes before halftime.
However, Claudelands pulled it back to 3-2 through Perry Katesmark to round out a high scoring first half.
In the second half Ngongotahā put the foot down and secured an impressive 5-2 victory with goals to Miller and Luke Barker.
Ngongotahā now have five wins, three draws and 18 competition points this season. They are one point ahead of ninth-placed Cambridge.
Their next match is against Papakura City at home. Papakura are in last place with three wins and two draws. Last time the two sides met they drew 0-all.
Northern Region Football League Division 2 results
Claudelands Rovers 2-5 Ngongotahā (HT: 2-3)
CLA: Jono Viviani 36', Perry Katesmark 44'
NGO: Yamil Casas 12' 41', Mitch Miller 22' 59', Luke Barker 79'
Northland FC v Bucklands Beach AFC – Match Abandoned
Albany United 3-3 Franklin United (HT: 2-1)
ALB: Alex McTiernan 21', Lee Robinson 35', Keagan Brophy 90+3'
FRA: Charlie Heather 5' 52', Darren Woolnough 55'
Onehunga Mangere United 2-0 Te Atatu AFC (HT: 2-0)
OMU: Ben Marumaru 28', Stefan Van Der Heijden 42'
Papakura City FC 0-3 Takapuna AFC (HT: 0-1)
TAK: Matt Hawke 1', Own Goal 58', Matt Chant 86'
Metro FC 2-1 Cambridge FC (HT: 1-0)
MET: Josh Chemis 40', Josh Dayal 81'
CAM: Jack Portegys 87'
