It was 25-year-old Smith's second game back after an 18-month injury layoff and he turned it on at Suncorp Stadium in front of 40,814 fans on Friday night.
Skipper and fullback James Tedesco, hooker Connor Watson and prop Nat Butcher were all superb.
It was the Roosters' fifth consecutive win over the Broncos at Suncorp and a complete reversal of their 50-14 loss to Brisbane in round one.
The Roosters played with more energy and their pack dominated their more fancied rivals.
The first half had several bizarre twists with momentum swinging, plenty of stop-start play, penalties galore and fiery confrontations.
There were several contentious moments.
Smith was sin-binned in the 19th minute for a high tackle with moderate force on fullback Reece Walsh, just when the visitors were on top at 8-0.
The Bunker got involved to retrospectively sin-bin Broncos forward Jack Gosiewski in the 30th minute for his high tackle on the visitors' lock Victor Radley.
Roosters second-rower Angus Crichton was put on report for an elbow to the throat of Broncos skipper Adam Reynolds.
Brisbane centre Kotoni Staggs was also booked for a late shot on Roosters five-eighth Sandon Smith.
Watson added to the "report-a-thon" when he too was booked for a hit on winger Jesse Arthars, who left the field with a category one HIA which he later passed.
Billy Smith leapt high with commitment and class to rise above Walsh to latch onto a Sandon Smith bomb and it was 8-0 after 15 minutes.
The Broncos were struggling to make any impact until freakishly talented winger Selwyn Cobbo swooped on a Sandon Smith pass and raced 50m to score.
Broncos skipper Adam Reynolds orchestrated a Walsh try with a double-pump pass that deceived the Roosters defence. Both tries were scored when Smith was in the bin.
The Roosters scored twice when Gosiewski was in the bin. Billy Smith did wonderfully well to ground a James Tedesco grubber kick before the dead-ball line, then Crichton crashed over after a scheming dart by hooker Connor Watson for a 20-12 half-time lead.
Walsh put Arthars over after the break to narrow the margin to four but the Roosters could not be denied. Butcher crashed over in the 65th minute off a Watson pass and the visitors hung on.
New Roosters half Hugo Savala, in his first starting game, gave a good account of himself.
Tedesco ran for 213m from 22 runs in a true captain's knock
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