Elias Lindholm scored for Calgary, which has lost two straight and 3 of its last four. The Flames were playing their third roadway game in 4 days and second in as many days.
Marleau and Couture each had a help on Meier's first objective of the season simply over 3 minutes into the video game.
Labanc scored midway through the very first to give San Jose a 2-0 lead. Erik Karlsson and Tomas Hertl assisted on Labanc's second goal of the season.
The Flames scored at 6:43 of the 2nd period, when Lindholm redirected T.J. Brodie's shot off a face off.
San Jose extended its result in 3-1 on Hertl's San Jose's first shorthanded objective of the season with 1:45 left in the second period.
Cam Talbot had 17 saves in his Calgary debut. The 31-year-old, signed an one-year free representative agreement with the Flames in the off-season after splitting time last season in between Edmonton and Philadelphia.
Tomas Hertl had a goal and a help to assist the San Jose Sharks beat the Calgary Flames 3-1 on Sunday night.
The 40-year-old Marleau invested the first 19 seasons of his career in San Jose and ranks initially in franchise history in points (1,085) and goals (509 ), among other categories. After 2 seasons with Toronto he was traded to Carolina during the summer and then had his agreement bought out.
Marleau signed a 1 year deal to return to San Jose on Oct. 9 and scored 2 objectives in his first video game back to lead the Sharks to their very first win of the season the next day. He has totalled 5 points in two games.