Sililoto made up for his earlier error by scoring his team's second try in the 25th minute after barging through multiple defenders. He combined well with hooker Troy Cullen, whose agility and speed up front were a delight to watch.
The hosts would have scored their third had Lama not spilled the ball while trying to clear from a ruck 15m from the Otamatea tryline.
In the 38th minute, Lama scored under the post after multiple phases of pick-and-go which had been the hallmark of Old Boys Marist.
The try preceded a brilliant run on the left flank by No8 Taniela Manu but he was brought down metres from the Otamatea tryline.
The visitors couldn't gain traction on the face of stubborn opposition defence coupled with woeful set-piece play. Yet, they turned down kickable penalties in favour of either lineouts or quick taps which often didn't yield the desired results.
Old Boys Marist's other try-scorers were first-five Matt Marwick, props Sililoto and Sione Kite, Lama, and fullback Bram Egli.
For Otamatea, flanker Kainga Pesaliti, wing Solomon Alaimalo and No10 Mona Paraki got on the scoresheet.
Otamatea coach Peter Robinson said the big score reflected a lack of players at training and failure to nail set-piece play.
"But we got tries in the dying stages and managed to get bonus point which will be critical in the later stages. We'll just have to keep working on it and try and get a win against Hikurangi next week," he said.
Shipton was disappointed they leaked tries in the dying stages: "We played well until the last quarter where we let ourselves down."
