Gold Coast competed gamely in the first half of their comeback match nine days earlier, trailing 14-6 at halftime before shipping 22 unanswered points to lose 36-6 to the Cowboys.
Fans may have feared a similar collapse when the Tigers again scored twice in the first 12 minutes of the second half, including an early try of the year contender finished by Joseph Leilua.
But the Titans again worked their way back into the match, levelling the scores at 22-22 heading into the final 10 minutes.
Gold Coast's decision to turn down a great field goal opportunity appeared costly when Marshall kicked the 16th field goal of his career to edge the Tigers ahead with less than four minutes remaining.
And the Titans again snubbed a handy field goal chance with less than two minutes on the clock but that proved the right call when the ball bounced up into Sami's arms in goal for the winning try.
The victory was the Gold Coast's first since beating the Broncos 26-18 in Brisbane on June 9, 2019.
In tonight's early game, the Newcastle Knights moved into second on the ladder, upsetting the Canberra Raiders 34-18.
The Knights led 16-6 at halftime, before two quick tries to Edrick Lee after the break grew their advantage to 22 points. The Raiders reduced the deficit to 10 with 20 minutes remaining but came no closer, suffering their first defeat of the season.