Julia Robinson, Mele Hufanga and Romy Teitzel all scored twice as the league-leading Broncos put down eight unanswered tries to finish off the Eels.
Elsewhere on Saturday, Cronulla pushed their way into the top four with a 12-8 win over Gold Coast and in a drama-filled 20-16 win by Canberra against the Warriors in Hamilton, two players were sent off.
The hosts played 46 minutes with 11 players after Matekino Gray was marched for a lifting tackle and Tysha Ikenasio followed her three minutes later for a hip-drop, becoming the second and third players to be sent off in 2025.
Brigginshaw, the third most-capped Jillaroo with 26 Tests, is now the most experienced NRLW player but will be joined by Sydney Roosters pair Keeley Davis and Isabelle Kelly on 50 when they face Newcastle in Gosford on Sunday.
"It's actually been a huge week. I'm so thankful for all the support across the game – been absolutely phenomenal," Brigginshaw said.
"I'm just really proud that we didn't fall away as we've done in previous weeks. But today we've proved to ourselves that's not us."
A milestone of a different kind came at Sharks Stadium when prop Caitlan Johnston-Green came off the bench in the 26th minute, just 12 weeks after giving birth to daughter Amarah.
However as Cronulla gained a key player, they lost another when Kiwi international centre Annessa Biddle (shoulder) was helped from the field.
"We'll have to send her for scans to see where she's at. But I don't think it will be short-term if I'm honest with you, so we're not having a lot of luck," coach Tony Herman said.
Scores were locked at 0-0 at the break, but the Sharks went down to 12 with Anne-Marie Kiria-Ratu sin-binned for a hip-drop tackle. It allowed Titans halfback Lauren Brown to find the gap on the left edge and score.
But two tries – to Emma Verran and Cassie Staples – in three minutes put the Sharks in front for the first time in the 50th minute.
The sides traded penalty goals and another confirmed a 12-8 Cronulla win.
"It just speaks volumes of the resilience in this squad," Sharks captain Tiana Penitani Gray said.
"It's not been easy with injuries and suspensions throughout the year but it's next person up. On the back of adversity comes opportunity."
The Raiders' first win off the season, after six straight defeats, was overshadowed by a courageous Warriors fightback and two players back in the sheds.
Winger Payton Takimoana bagged a hat-trick, almost getting the visitors home after trailing 16-0.
