Jacoby, Cox, Taylor and Peters now have a silver NZ Golf medal to sit alongside their gold won last year.
Jacoby, along with partner Nathan, is the NZ mixed foursomes champion and will defend this title in Maraenui over Labour weekend in October.
The win was Waikato's third after triumphs in 2005 and 2013.
Waikato's team total, while the best on the tough short Inglewood course, was 23 points lower than Northland's 2017 winning score.
Inglewood is known for its numerous par threes and only two par fives, making par for the course just 68. Water hazards feature on all but one hole and with tight lies, proving a challenge for many of the 56 district master players assembled for the 2018 championship.
The format of the tournament, which has not changed in 27 years, is based on the cumulative total of the best three gross stableford points totals per team of four in each of the four rounds.
Jacoby produced the best individual round for Northland, securing 34 stableford points in the opener.
The tournament is due by venue rotation to be held in Tasman in 2019.