"It was difficult conditions with absolute gale-force winds from one end of the wicket," he said, but he lauded the James Pamment-coached Knights for batting intelligently in the inclement weather.
ND opener Daniel Flynn scored 72 from 69 balls before falling prey to seamer Andrew Mathieson in the 24th over.
Flyn forged a 74-run partnership with Daryl Mitchell, who contributed 64 at first drop.
All the CD bowlers went for above 5.86 runs an over with The Station Napier Old Boys Marist opener Mathieson the most expensive at a shade under 10.
"We [the bowlers] started pretty steady but they [the batsmen] struck at the back end and got away with it," said Nethula, who claimed 2-48 and is sitting second on the trophy bowling rankings with nine scalps to date, one above Auckland Aces left-arm strike bowler Mitchell McClenaghan.
Seamers Seth Rance and Bevan Small also claimed two wickets each.
"It's nice to get a few [wickets] but it'd be nicer to contribute particularly to winning games," he said.
The Heinrich Malan-coached Stags' wheels came off in 24.5 overs to be all out for 104.
Opener Jamie How, who is the top run scorer in the competition with 315 to date, scored 25 from as many balls before he was run out while Nethula was unbeaten on 25 at No8.
ND opening bowler Scott Kuggeleijn claimed 4-31 to show why he is perched a rung above Nethula with two more wickets so far in the limited-overs campaign for the 2013-14 HRV Cup Twenty20 champions and Ford Trophy leaders.
The Stags, who have slipped to fourth place, host Canterbury Wizards at the same venue on Wednesday. The Otago Volts v Wellington Firebirds in Dunedin was abandoned without a ball bowled.