Fundora made her team promise there'd be no tears during her world title fight. Her brother broke the promise.

PHOENIX: Before Gabriela Fundora walked to the ring to fight for her first world title late, last year, she made her family and entourage promise one thing — no tears, regardless of the result.

Fundora, despite entering only her 12th bout, boxed like she belonged on the highest of stages all along as she landed 35 punches from 87 shots thrown in the opening two-minute round alone.

Fundora peppered Mucino with punches and flurries in the second and third rounds, planting her feet a step from her opponent, sometimes waiting for her to throw, before countering with a one-two, every now and then a three.

In the fourth, Fundora rocked Arely Mucino's skull back with a southpaw left straight, and didn't even let her get her head back into position before pummeling her further with a well-placed combo to the bones before Gabriel Santillan shocked the boxing world with a big win over Alexis Rocha in Inglewood.

Mucino was game but ultimately outclassed as Fundora dropped her in the fifth after a succession of left-rights and then a right-left.

Though she made it to her feet, Mucino looked off-balance. Regardless, the referee allowed her to continue, only for Fundora to close the show with a corner stoppage later in the round.

Fundora had done it — a legit world championship win at 21 years old.

Only, there was one family member who was about to break that promise of no tears — her brother and biggest supporter, Sebastian.

"I was really happy," he told ProBox TV this week, cheering his sister on as she defends that strap for the first time Saturday against Christina Cruz at a Golden Boy Promotions event inside the Footprint Center in Phoenix, Arizona. Jaime Munguia takes on John Ryder in the main event.

"Really happy," Sebastian reiterated. "I almost got watery eyes when she won that title, but the camera was on us and I was like, 'I can't cry right here! I'll go cry in my room later'.

"I was super happy. She's always working next to me and she works so hard, so she can do everything I can do."

Gabriela said: "Before we went out to fight, I made sure to tell my team, 'Do not cry. I don't want to see no tears.' So, then Sebastian is getting watery eyes and I'm like, 'Oh my goodness!'

"But, afterwards, I think we just went home … my wish was filled."

Gabriela and Sebastian have long had a sibling rivalry — and even needled one another as to whom would win the race to become the first champion-winning boxer in the Fundora family.

Though Gabriela won, Sebastian has his own shot March 30 when he takes on Serhii Bohachuk in a bout which has the vacant WBC junior middleweight world championship on the line after the organization stripped Jermell Charlo of the belt.

Winning a world championship "is going to happen for Sebastian," Gabriela confidently told us.

While inseparable from one another at boxing events, Gabriela enters the ring alone to compete against Cruz, and said she "can't wait for you guys to see fireworks," at Thursday's final press conference.

Speaking backstage to ProBox TV, Gabriela said she trains for knockouts through "hard work — it's no secret."

She added: "You can't expect to reach your goal or destination, whatever it is, if you're only doing it half way, and not even putting 100% into it.

"So, whatever you do, not just in boxing but in life, in general, you put 100% into it so you can go and reach your goal."

Can fans expect another Fundora finish Saturday night live on DAZN, then? "Of course," said Fundora. "That's what we train for."

After Saturday, she does not have a dream opponent to fight, just whoever has the belts. She wants to be an undisputed champion.

On this form, few would bet against her.