The Fort Worth Stock Show & Rodeo picked its grand champion on Friday and sold at auction for $205,000 on Saturday.
"This has been our lifelong goal, and to do it with one that we raised by ourselves, it makes it even better -- it just adds to the excitement," said 12-year-old winner Stock Martin, of Hereford.
Lunchbox was born a month premature but, even then, the steer always looked good, Martin said.
"We knew we had a good one when he was born, so me and Dad thought, 'Well, everybody at the show might as well pack their lunch, because we've got one that'll get 'em.'"
Lunchbox sold at auction Saturday for $205,000.
"This little boy was there early in the morning before school, you know, late at night before bed, feeding and taking care of this animal, so we just think it should be rewarded," said winning bidder Kris Davis.
Martin, who plans to attend Oklahoma State University, said on Friday he already has plans for the money.
"Put it back into college and then buy more steers, maybe win some more shows," he said.
Last year's grand champion took home $230,000.
The Fort Worth Stock Show and Rodeo tweeted Saturday afternoon that the junior sale of champions set a new record, $3,126,108.
Saturday is the last day of the Stock Show, gates close at 8 p.m.
NBC 5's Andres Gutierrez contributed to this report.