Former Titan James Roberts, who had appeared to be struggling with a hip injury for most of the evening, ended his old club's fightback by securing a penalty which Kahu kicked to seal the win.
The Titans' fast finish was in stark contrast to the start of their evening.
Prop David Shillington succumbed to a hip injury in the warm-up and then Roberts, Gold Coast's enemy No.1 in the build-up to the game, ghosted past John Olive to open the scoring inside four minutes.
Roberts nearly turned provider a few minutes later when he steamed into a gap but Anthony Milford couldn't hold his inside ball and a chance went begging.
The Broncos did extend their lead in the 24th minute when Ben Hunt dummied his way through on a fifth-tackle play for his third try in his past five games against the Titans.
Gold Coast rallied with David Mead, who had earlier made a great try-saving tackle on Corey Oates, capping a fine individual half when he got on the end of an Ash Taylor grubber.
Broncos coach Wayne Bennett said after last weekend's nailbiting golden-point win over North Queensland, the Titans' clash had all been about points, not performance.
"Coming off a big win last week, it's hard to back up and get a good win," Bennett said. "They're good this team. They did a good job. "We got the job done. Got the two points."
Titans coach Neil Henry praised his team's never-say-die attitude, conceding the Broncos are just a better team at this stage.
"If we stay resilient like that we'll win a few games, just not tonight," he said. "It is significant it didn't blow out to 30 or 36.
"We just haven't gone into our shell, I just think we need to back ourselves a little bit earlier than that."
Henry also revealed young half Taylor hurt his shoulder during the game and will have to be assessed during the week.
-AAP