The clash between Grundy and former teammate Max Gawn was an eye-catching duel even if it did not greatly influence the result as Sydney surged in the last term to clinch a 22-point triumph over Melbourne in the season-opener on Thursday night.
It was instead the Swans' undermanned midfield bolstered by Isaac Heeney spending more time at the goalface that propelled the hosts to a 12.14 (86) to 9.10 (64) win at the SCG.
Heeney lined up at the first centre bounce and went on to be the most impactful player around the stoppages in a role that has been much-teased since his debut season in 2015.
The 27-year-old led the way against the Demons' star-studded midfield in the absence of skipper Callum Mills, Luke Parker and Taylor Adams, with 26 disposals (18 contested), 13 clearances and a goal in a superb display.
Chad Warner (26 disposals, one goal) added valuable support in the second half after only eight touches before the break, as Tom Papley (20, one) also spent time in the middle while adding a spark up forward.
Half-back Nick Blakey was just as crucial after half-time as the Swans looked to lower their eyes more when moving the ball forward after Demons defender Steven May had dominated the air.
Clayton Oliver showed few signs of a disrupted pre-season as he returned to the Demons' senior set-up for the first time this year and immediately made his mark.
The star midfielder might not have been quite as clean as usual but made his presence felt with 29 disposals and six clearances as the Demons stayed in touch until the final term.
There were no concerns with Christian Salem's ball use as the smooth mover shifted from half-back and into the midfield as the Demons looked to get more from their forward 50 entries.
But it was Jack Viney who stood tallest in the Melbourne midfield with a game-high 31 disposals (14 contested) as well as seven clearances, seven tackles and two goals.
Bayley Fritsch booted four goals for the Demons, including three in a blistering third term that looked like turning the match in the visitors' favour.
The Swans led by only two points at the last change but slammed on five goals to two to race away and start their 150th season in fine fashion.
SYDNEY 3.3 4.3 7.10 12.14 (86)
MELBOURNE 1.6 2.8 7.8 9.10 (64)
GOALS
Sydney: Hayward 2, McLean 2, Florent, Fox, Heeney, McDonald, McInerney, Papley, Warner, Wicks
Melbourne: Fritsch 4, Viney 2, Langdon, Petracca, Van Rooyen
BEST
Sydney: Heeney, Grundy, Blakey, Warner, Papley, Florent, Rampe
Melbourne: Viney, May, Salem, Petracca, Oliver, Gawn
INJURIES
Sydney: Nil
Melbourne: Bowey (shoulder)
SUBSTITUTES
Sydney: Sam Wicks (replaced Joel Amartey in the third quarter)
Melbourne: Jack Billings (replaced Bailey Laurie in the third quarter)
Crowd: 40,012 at the SCG