Nonu, who was sensationally dumped by then coach Mark Hammett at the conclusion of the 2011 season, returned to the Hurricanes for his final campaign before he heads to France after two years at the Blues and one with the Otago Highlanders.
The match at Eden Park was his 122nd appearance for the Hurricanes, who made seven changes to their starting side from last week's tense 22-18 victory over the Waikato Chiefs.
Coach Chris Boyd had made five changes before the game and winger Cory Jane and lock James Broadhurst were late withdrawals.
Jane's withdrawal forced a major rejig of the backline with Otere Black coming in at flyhalf and James Marshall shifting to fullback while Nehe Milner-Skudder moved to the right wing.
Even with all of the changes, the table-topping Hurricanes were too strong and disciplined for the Blues, who are also in turmoil off the field as debate rages over the future of coach John Kirwan.
The Hurricanes dominated first half territory and possession but only capitalised in the final five minutes with tries to prop Chris Eves, his first in Super Rugby, and scrumhalf TJ Perenara.
Black converted both to go with his ninth minute penalty to give the visitors a 17-0 lead at the break.
The Hurricanes again strangled the Blues of possession and were patient creating pressure inside Auckland's territory in the second half with tries to hooker Dane Coles and Milner-Skudder, who sealed the bonus point.
The fourth try moved the Hurricanes to 57 competition points and virtually ensured they would qualify in top place, with only the Chiefs (44) and Highlanders (39) capable of surpassing them on the table with three full rounds of matches remaining.
Blues' replacement back Matt Vaega scored his side's only try. – Reuters
Original source: Hurricanes qualify for play-offs