The win moved Thunder level on points with third-from-bottom Derby Trailblazers, although only after they nearly blew a 28-point half-time lead.
Thunder led 52-24 at half-time but Brixton came back into the game in the second half and trailed by just a point, at 74-73, with 1min 26sec left.
However, Worthing held their nerve to get the win and coach Daniel Hildreth said: “Having played some of our best basketball of the season in the first half, reflected by the score and with us exceeding our goals, we then took our foot off the pedal and played some of our worst basketball of the season. Our effort levels and discipline were the things that concerned me the most.
“When I went back to the locker room, the guys’ mood was like we lost this game. Either way, though, we have won the game and that is the priority.”
Dominic Baker got the ball rolling for the hosts as he hit Thunder’s first five points to give them an early 5-2 lead, but Topcats hit back to tie the game numerous times in a scrappy first five minutes.
Worthing, though, led by Hank Rivers, saw their lead balloon as the first period came to a close and they led 23-11 thanks to a 14-2 run.
The game looked to be won in the second quarter, as Worthing asserted their dominance, defensively, while scoring freely at the other end. Buckets by Nick Corbin, Rivers and a triple from Baker gave the hosts a 45-19 lead with 1-57 left in the half.
With relegation a serious threat for Thunder, the players hounded Brixton every time they got the ball and even when the visitors went to the foul line – they shot poorly – connecting on just one free throw from six attempts in the first half as Thunder led 52-24 at half-time.
Brixton came slowly back into contention in the third quarter, as Thunder looked to relax on their lead too easily.
A 10-0 run by the visitors reduced the gap to 61-43 but Thunder led 63-45 after three quarters.
A 9-0 Brixton run cut the gap to nine points, before two free throws from Brendan Okoronkwo restored Thunder’s double-digit lead.
Brixton responded well and continued to close the gap, reducing Thunder’s lead to one point, but Kadiri Richard blocked a shot from Vytenis Petkus with two seconds remaining and Bud Johnston then sank a free throw to seal Thunder’s win.
Johnston led Thunder with 18 points, Hank Rivers had a double-double of 12 points and 11 rebounds and Dominic Baker added 11 points.