Blackman stole the show by passing for 535 yards and six touchdowns.
But things looks good for Long Beach early as the Vikings actually led 14-0 midway through the first quarter.
Sophomore defensive back Thomas Mahoney returned a fumble 25 yards for a touchdown at the 14:40 mark and on LBCC's first offensive play freshman quarterback Kevin Lubner connected with sophomore wide receiver Darrius Young for an 80-yard touchdown strike at 8:51.
Harbor tied it at 14 after a pair of Blackman TDs before freshman David Covey’s 28-yard field goal gave the Vikings the lead 17-14.
Blackman tossed his third TD of the first quarter, a 38-yard pass to Dwayne Frampton to give Harbor the 21-17 advantage.
On the ensuing kickoff, Young earned his second touchdown of the night with his 83-yard KO return. Covey extra point try was blocked and LBCC had its final lead of the night at 23-21.
Harbor took over and went on to score 21 unanswered points to go up 42-23 before freshman Tyrone Martin’s four-yard TD pass from Lubner at 9:26 in the third broke the string.
Sophomore Brandon Joseph added a pair of receiving touchdowns to close out the scoring for Long Beach.
The Long Beach defense was unable to contain Harbor as the Seahawks totaled 737 yards of total offense in the contest.
For Long Beach, Lubner 11 of 25 passes with one interception for 182 yards and three touchdowns. Jospeh led LBCC receivers with five receptions for 49 yards and two touchdowns.
Young totaled 232 all-purpose yards (3 KO returns for 152 yards, 1 reception for 80) with two touchdowns.
After a big loss, things won’t get any easier for the Vikings. Long Beach (0-1) travels to face rival El Camino College next Saturday (Sept. 12) for the Battle Axe.