The Sixers were sent in at the SCG ahead of Smith's only game before the Pakistan Test series and the star batter picked up where he left off from last summer's blistering cameo.
Smith opened and scored 61 from 42 balls, with seven fours and a six.
During a 69-partnership for the third wicket with a favourite co-conspirator in Moises Henriques (40), Smith helped the Sixers steady themselves after losing 2-2 from Will Sutherland's bowling early on Friday night.
Smith brought his seventh BBL half-century with a single off Sutherland, who finished with 2-21.
It took long-time Australian teammate Adam Zampa (2-24) to dismiss Smith in the 17th over and prevent the all-out carnage that had crowds flocking to see him last summer.
Also playing his first match on home soil since their one-day World Cup triumph, Zampa enticed Smith into skying a shot to deep square leg, where he was caught by Jono Wells.
Zampa threatened to turn the game on its head as he bowled English all-rounder Tom Curran for a golden duck with his next delivery, but he missed out on his maiden BBL hat-trick.
Nevertheless, the leg-spinner halted the momentum, something the Sixers only regained in a 17-run final over that featured two sixes from Jordan Silk (26no off 14 balls).
A rare clash for Smith with Test teammate Nathan Lyon was put on ice as the superstar off-spinner missed the game to ready himself for next week's Perth Test.
Smith is hoping to play for the Sixers once more this summer in a clash with the Sydney Thunder on January 12, that falls between the Pakistan and West Indies Test series.