Gilchrist still has Australian cricket fans talking about his astonishing 120-ball 113 which dramatically changed the course of this week's final cricket Test against Pakistan into a resounding nine-wicket win for Australia at the Sydney Cricket Ground.
The sweet-hitting left-hander has now scored 13 centuries, the most by a wicketkeeper in Test cricket.
Without Gilchrist, the Australian side had been superb. With him, it became nigh unbeatable, and indeed Australia won the first 15 Tests Gilchrist played in.
This week's Sydney Test provided Gilchrist with his 50th win in 65 Tests - an unprecedented success rate for a Test cricketer.
Marsh, who broke the keepers' duck by making an unbeaten 110 in the Centenary Test against England in Melbourne in 1977, is in awe of Gilchrist's ability with both gloves and bat, and rates him as probably the best cricketer in the world.
"It's a difficult thing to judge, obviously, with players like Tendulkar, Lara, Kallis, Warne ... but if you sat down to pick a world XI he'd have to be your first choice," Marsh told Australian Associated Press on Thursday.
Former Test skipper and prominent commentator Richie Benaud describes Gilchrist as the cleanest striker he has ever seen, and fellow commentator Bill Lawry compares him with Bradman as a destructive force.
"I never saw Bradman bat, but it's hard to imagine he could have been any more destructive than Gilchrist," said Marsh, now director of England's national academy.
"He has such tremendous bat speed ... a great wrist cock which gives him such a free swing of the bat.
"He just thinks about striking the ball before he ever thinks of defence. The swing of the bat is so natural and uninhibited.
Marsh, who helped shape Gilchrist's career when he coached him at the Australian Cricket Academy in the early 1990s, believes the key is the freedom Gilchrist brings to his batting.
"I don't think he ever thinks about getting out. If he thinks of anything while he's out there, he thinks about hitting the ball."
Australian coach John Buchanan is another unabashed Gilchrist fan.
"His game just happens to be one of rapid fire and he's got a huge range of shots be it against spin or pace," Buchanan said.
"No matter what the situation is he responds that way. It's the ability to make good decisions and follow them through that allows him to do what he does.
"And to be the highest Test-scoring wicketkeeper, batting at No.7 most of the time, is just incredible."
Wisden officially rates Gilchrist the fastest scorer in Test cricket history, with a sustained strike rate well over 80 runs per 100 balls faced, at an average of nearly 53.
"The thing about Gilchrist is he can change the course of a match in an hour. And he doesn't just do it once or twice, he does it regularly," Marsh said.
"Effectively he gives Australia an extra player - and what a player."