Hamilton, heading for a second loss in the first two games under coach and former All Whites player and coach Ricki Herbert, had opportunities, but so did HBU, who planted two more at Wanderers custodian Matt Oliver who was more than up to the task.
Coach Brett Angell, disappointed that some of the finishing didn't match the buildup work, said had either one found the mark it may have been a completely different game.
Hawke's Bay next face a home match against defending champions Team Wellington on Sunday, by whom the club was beaten 4-2 at Bluewater Stadium in the first round last year. They drew 3-all later in the season in Wellington.
"We are under no illusions," said Angell.
On Saturday Team Wellington beat Wellington Phoenix Reserves 5-2 in the capital city derby while, in other games yesterday, Eastern Suburbs beat Southern United 1-0 in Dunedin, Tasman United beat Canterbury Dragons 1-0 in Christchurch and, in an all-Auckland affair, beaten 2016-2017 finalists Auckland City hammered Waitakere United 5-0.