He took the first-day lead in the March 14-17 Sabine River Challenge, the season opener of the Bassmaster Elite Series.
Pierre Part's Cliff Crochet was in third going into the second day with 13 pounds, and Gonzales' Greg Hackney grabbed the fifth-place slot with 11-13.
Click here to see full results.
Rojas' 15 pounds, 10 ounces kept him in front of Mark Davis of Mount Ida, Ark., who was second with 13-13.
"It must be the water," Rojas laughed, a hint that his fast start in the 2013 season opener was almost a coincidence to his success on Toledo Bend, where he won an Elite event in 2011, one of several victories on that fishery over the course of his career.
"I don't even think that the water I'm fishing really does come from Toledo," he speculated.
"Here, you have to find the right area. There's so much water, and it takes so much time. I was able to find an area that's got them," he said.
Make no mistake: From an angler's perspective, Toledo Bend Reservoir and the Sabine River system are polar opposites.
The Sabine system is a river fishery with cuts, bayous, canals and so much backwater that the trick for the pros in this Elite tournament — as Rojas said — is to narrow down the choices and then pick it apart. Toledo, another great fishery, is all about reservoir fishing.
Rojas said he's making a long run into Louisiana, but he didn't reveal any details other than that Thursday he caught seven keeper bass, plus four that didn't measure up to the 14-inch limit.
One of his keepers was a 5-pound, 15-ounce largemouth, which leads the way in the contest for the $1,500 Carhartt Big Bass bonus to be awarded at tournament's end.
The 5-15 was his first fish of the morning — and it surprised him.
"I thought it was a dogfish [a bowfin] at first — they both pull hard. But it wasn't, it was a big bass. I'll take it," he grinned.
"It's so nice to have a fish like that the first day. It's what separates you from everyone else."
Most important to his game plan, the catch gave him a major clue.
"It told me what I needed to do," he said.
With 15-10 on Thursday, the leader became the first contender for the event's Berkley Heavyweight bonus of $500 awarded to the angler with the largest single-day bag.
He said one key to his first-day success was he was able to find clear water, to which the bass tend to gravitate. Rojas said he'd attempt to duplicate Thursday's success by returning to the same area.
"I just have to make it last for four days," he said.
Davis, in second place, said his first fish was a 4-pounder.
"Things just kind of fell into place after that. I had nine keeper bites, and I did not anticipate that at all. I was pleasantly surprised. It had been a slow practice," said Davis, well-known as the pro who captured the sport's two biggest honors in the same year, the Bassmaster Classic and Toyota Bassmaster Angler of the Year in 1995.
He topped that accomplishment with two more AOY titles in 1998 and 2001.
Louisiana native Crochet said the bayous, canals and backwaters of the Sabine system are much the same as the fishery he grew up with in his backyard.
"We've had front after front over the past few weeks, and that's made the fishing challenging," he noted.
In fourth place was Elite rookie Hank Cherry of Maiden, N.C., who brought in 12-11.
Just last month in his first Bassmaster Classic appearance, Cherry finished third. That, perhaps, was when he worked through any jitters he might have had going into his first Elite event.
"I'm not nervous at all. I've been waiting for this my whole life; I'm as happy as I can be," he said.
Fifth place was taken over by Greg Hackney of Gonzales, La., with 11-13.