He batted throughout the 40 overs, ending unbeaten on 74 off 117 balls as Hayling posted 164-5 after skipper Rob Cordell had elected to bat first.
The only other double figure score in the innings belonged to Matt Colban (47) who helped Hallett add 82 for the third wicket against Ben Bradley (3-27).
Sarisbury’s reply got off to a dismal start when Freddie Steele (3-21 off eight overs) dismissed opener Keith Hammond for a duck.
He then removed Chris Mottola (18) and skipper Chris Bolton (0) as Sarisbury dipped from 31-2 to 40-5.
Bradley (28) and Max Martin (23) hung around for a while but Colban (3-7) - the seventh bowler used by Hayling - mopped up the tail as the visitors slithered from 83-5 to 100 all out at Hayling Park.
Jubin Karippai compiled the game’s only half-century as Kerala won their city derby with US Portsmouth at Rugby Camp.
Asked to chase 164 for victory in the Division 3 South fixture, Karippai hit 63 as Kerala triumphed by two wickets with almost nine overs in hand.
Their reply had begun badly when openers Prajan Kallidil (0) and Presh Prasad (4) were out cheaply.
But Karippai kickstarted the recovery and, helped by Nimal Valsan (32) and skipper Dawn Ambi (20), Kerala looked on course for a comfortable victory on 132-3.
Hamid Khan (4-23 off eight overs) did his best to wrestle the initiative back towards US, as Kerala slipped to 149-7.
But Pranav Pathiyarappattu compiled a key innings of 12 not out to see his side to victory and leave US rueing the 26 wides they sent down in a total of 30 extras.
Earlier, US opener Raj Das (48) and Seshadri Nadathur (41) had top scored as US, put into bat, had posted 163-5 off their 40 overs (Linson Poulose 2-39).
Charlie Kemp hit an unbeaten 69 as Fair Oak 2nds caned Cadnam by eight wickets in only other Division 3 South fixture to be completed at the weekend.