Batsman Tom Tremain then anchored his team's run chase with 53 not out, as PNBHS reached 96-2 in the 25th over.
Collegiate were able to redeem with the bat against Havelock as they raised 241-6 from their 50 overs on the back of a superb 108 not out from Simes.
Coming in at 48-2 but losing his middle order partners, Simes finally got support from Ben Kelt (60) as they batted from the 18th to the 48th over and put on 157 runs together.
Simes took runs wherever he could find them, with two boundaries and a six in his 132 ball knock.
The bowlers then held Havelock to 181, bowling them out in the 46th over.
There was some resistance from the middle order but Beau Hourigan took the key wickets on the way to getting figures of 4-43, while Jo Abernathy (2-18) helped him clean up the tail.
Meanwhile, former Collegiate old boy and Central Districts opening batsman Ben Smith finished the Plunket Shield campaign as part of his team's three wicket over Auckland at Napier's McLean Park.
Smith made scores of 25 and 26 as the Stags came from behind on the first innings to reach 301-7 after Auckland declared after their second turn at bat.
Another Collegiate old boy and Black Caps T20 player Tom Bruce made 43 in the run chase.