Central Coast has scored back-to-back wins in a season for the first time in more than three years, putting a dampener on Macarthur FC's inaugural home A-League match at Campbelltown Stadium.
Daniel De Silva's 35th-minute goal and a clincher by Jordan Smylie in the 89th secured the 2-0 result for the visitors following their opening round win over Newcastle.
Both goals came with seemingly little doing and largely against the run of play.
After a dour opening quarter, a scything run by Joshua Nisbet down the right flank brought the match alight.
The midfielder slid in a neat cross for De Silva who fired past Bulls 'keeper Adam Federici to make it 1-0.
The Bulls stepped up their game thereafter but struggled to make the last shot count.
Spaniard Benat Etxebarria had back-to-back shots charged down in the 60th minute after striker Matt Derbyshire had dragged his shot across goal moments before.
The introduction of Lachlan Rose, a standout for the Bulls in the win over the Jets, and Liam Rose, added some much-needed spark for the home side but they couldn't conjure the goal they needed.
As the match wound down, the subs took over - but it was the reserve trio of Smylie, Lewis Miller and Daniel Bouman who did the ultimate damage.
Miller's long ball found Bouman marginally onside and with no defence at home he laid off for Smylie to score the simplest of goals.
It marked the first time since November/December 2017 that the battling franchise had won consecutive games in a season, when they defeated Wellington and Perth.
After a horror 11-match losing run that began in January last year, the Mariners have now gone five games undefeated across two seasons.