Marshall lasted just three minutes before he was forced off the field after injuring his left knee during what looked like a regulation play.
Club officials fear Marshall has damaged his anterior cruciate ligament, which would require a full knee reconstruction and could rule him out for the season.
He will undergo scans on Monday.
The Kiwi international has endured a torrid run of injuries, missing large chunks of the past two seasons and undergoing shoulder surgery five times.
Despite the loss of their star five-eighth the Tigers raced away to a 24-4 lead just after halftime and held off a late Dragons revival.
The Tigers opened the scoring in the seventh minute when Fulton pounced on a John Morris grubber kick but the Dragons hit back through Gasnier in the 15th when he barged past three defenders to cross out wide.
Dragons fullback Josh Morris dropped the ball cold from the restart, and the Tigers made them pay with Lawrence striding over out wide.
The Tigers then extended their lead in the 23rd minute when Farah made a trademark scoot from dummy half and crossed under the posts.
Moltzen, in his NRL debut, gave the Tigers a handy lead in the 50th minute after getting on the end of a clever Farah grubber kick.
But Soward hit back five minutes later, slicing through the defensive line to score under the posts for the Dragons.
Rangi Chase put Reynoldson through with 11 minutes on the clock but the Dragons ran out of time.
The win was reminiscent of the Tigers' effort in round eight last season, when they went on to beat eventual premiers Melbourne 30-12 despite losing Marshall to a shoulder injury in the fifth minute.