They hit Whanganui fast and hard on their carries and looked work wide and use their kicking advantage with the wind – centre Chance Malu and double try-scoring No8 Jekope Kitau impressive, while second-five Stewart Cruden did well with the boot, as did expat Whanganui first-five Kody Edwards.
A couple of broken tackles and a defensive lapse and the home side were through to nab four tries, the first to another expat in fullback Adam Boult.
The second half, with Whanganui having the wind, turned into a scrappier affair, with plenty of lost ball from both sides as they ran on their deep benches and switched players around positions.
Notable for the Evergreens that ex-Collegiate lad Waqa Nalaga scored one of the second stanza tries, while 2020 Whanganui player Logan Henry got to run the cutter.
However, their lineout struggled whereas Whanganui's – which had apprentice player Mason Johnson, ring-in Matt Ashworth, and No 8 Semi Vodosese as the jumpers – showed fairly good co-ordination.
Leaders underneath skipper Dane Whale, who covered fullback, were in short supply, but without the likes of Jamie Hughes, Josh Lane and Peter-Travis Hay-Horton, Whale's brother Ben played the full game covering both blindside and openside, giving a typically strong effort.
Two of Whanganui's tries came from their apprentices – Johnson and speedy winger Jack O'Leary - while reserve hooker Jack Yarrall had a very busy second half, and reserve fullback Peceli Malanicagi looked a handful out wide.
Up front, the side welcomed former Rangitikei schoolboy Adam Coll as import prop, having been a College Old Boys RFC regular who lost much of his 2022 MRU club season to injury, thus not being in contention for local rep honours.
Props Keightley Watson and Tai Pulemagafa did well in their first hit-outs for the Whanganui senior team, the former being denied a try by just inches in the second half, while apprentice forward Kohlt Coveny received a warm reception from the travelling supporters when he jogged on, covering flanker instead of his usual hooker role.
Without Timoci Seruwalu in the midfield, while Brook Tremayne ran the Whanganui cutter for the first time, partnering with newcomer Caleb Gray and try-scorer Kahl Elers-Green in the halves, there was not always the fluidity through the backline which can only come with practice.
"We talked about the pace of the game, what [Evergreens] were going to bring, how we could absorb it, and I thought, bar a couple of things, we did that really well," said Hamlin.
"In the second half, we probably went one-off a little bit too much, but we were able to get over the game line so we got away with it.
"But it wasn't really what we were after. But we saw on the last try [Elers-Green], that's the structure we want to see.
"The work-on for us is maintaining a bit of composure, keeping enough ball, and when we've got the ball and being able to maintain possession and pressure, they looked just like us running backwards.
"The things we asked for around the attitude and the effort areas, were there.
"Does their execution have to be better? Yeah. But we expected that going in."
Whanganui had been eager to find wide gaps in the final quarter, but the desperation to get out there led to mistakes against Evergreen's cover tackling.
"While we stretched them, we needed to carry a little bit more direct, bring them in, be a little bit more patient and we probably could have had a couple more tries."
Hamlin welcomed Coll, although accepting he was a bit short of a run.
"This Covid environment, dropping players in week in and week out, we're going to need more props anyway, every game.
"It might be I'm carrying five to six props, which is what we had today."
Hamlin praised Ashworth and Johnson for stepping up, while he thought O'Leary as outstanding on the wing after a club campaign in the midfield.
Manawatu Evergreens 38 (J Kitou 2, A Boult, M Hala-Ngatai, W Nalaga, N Tato tries; S Cruden 3 con, K Edwards con) Whanganui 15 (M Johnson, J O'Leary, K Elers-Green tries). QT: 14-5; HT: 26-5; 3/4 T: 33-10.