But he showed just why selectors have kept the faith, taking four wickets to leave the field as Australia's best bowler in his first Test since being parachuted in on Boxing Day against India last summer. The West Australian swung the ball more than any of his teammates and he got it hooping both ways to cause havoc.
"I've certainly worked hard the last five months to get an opportunity again," Marsh said. "When you have setbacks you always think the worst, I thought I might not play again after a summer like I had last year.
"There has been no secret recipe, I just worked my bum off hoping t get another opportunity. Today was a really pleasing day.
"In the past my role has been to hold up an end. JL (coach Justin Langer) came up to me before the start of play and at lunchtime and said, 'Go for it, attack, bowl the way you want to bowl'.
"I was a little bit, not shocked, but it gave me great confidence to go out there and give everything I had. Maybe a change of mentality allowed me to bowl a bit more attacking. It was fun."
Marsh's first wicket was the third of the England innings when danger man Ben Stokes top edged a pull shot on 20 that was caught by Nathan Lyon at point. An emotional Marsh let out a visceral cry when Lyon pouched the catch, showing how much it meant to him to be back wearing the baggy green.
The 27-year-old continued his middle order demolition job when he set Jonny Bairstow up beautifully, bowling outswinger after outswinger to the right-hander before surprising him with a yorker-length inswinger that had him plumb LBW for 22.
Next up was Sam Curran, who was caught by Steve Smith at second slip swishing at a wide ball then Marsh picked up wicket No. 4 when another in-ducker hit Chris Woakes on the pad right in front of his stumps for two.
Marsh was Australia's most economical bowler as well as its most destructive, conceding just 2.16 runs an over as he strangled the life out of England after tea, finishing with figures of 4/34 after 16.1 overs before he stopped bowling because of cramp.
Plenty of pundits were questioning why Paine won the toss and bowled but while England threatened to make him pay, as has been the case so often this series, it let Australia back into the game.
Pat Cummins and Josh Hazlewood bowled well in the first hour but the runs still flowed and Joe Denly was the only batsman to fall, edging Cummins to Smith at slip for 14. Rory Burns and Root made things look easy as the sun shone brightly and the pitch flattened out, combining for a 76-run partnership as the home side went to lunch just one wicket down but both men failed to capitalise on promising starts – as did a host of others.
Burns was out for 47 miscuing a half-hearted pull shot that was swallowed by Marsh at mid-on before Root (57) followed Stokes, bowled by a Cummins pearler that angled in and straightened to smash into off stump, in almost identical fashion to how the Aussie quick knocked Root over in the second innings at Old Trafford.
Marsh then took three wickets on the trot before Hazlewood came back into the attack to dismiss Jofra Archer caught behind.
Buttler took matters into his own hands and went on the offensive, smearing Hazlewood for consecutive sixes down the ground then swatting the big quick over the leg side for another maximum a few overs later as he brought up his fifty.
Buttler followed that up by reverse sweeping leg-spinner Marnus Labuschagne to the fence and it didn't take long for Paine to put all his fielders on the fence to try and limit the damage the aggressive right-hander was doing.
Paine will need to figure out how to stop Buttler's six-hitting ways when play resumes on day two.
Australia has broken an 18-year Ashes hoodoo, winning the urn on English soil for the first time since 2001 with a thrilling 185-run victory in the fourth Test at Old Trafford.
The Aussies have taken an unassailable 2-1 lead in the series with one match left to play. Even an English win at The Oval and a 2-2 final result will see the tourists leave British shores with bragging rights because they won the last series Down Under in 2017/18.
Not since Steve Waugh was captain just after the turn of the century have Australian cricket fans had the chance to celebrate an away Ashes triumph. Now captain Tim Paine and coach Justin Langer will forever be remembered as the brains trust that masterminded a historic chapter in Australia's cricket history after four straight Ashes series losses overseas in 2005, 2009, 2013 and 2015.
"That feels amazing to know the urn's coming home now," Steve Smith told Sky Sports.
"It was always one I wanted to tick off my bucket list to get the urn over here … to know that's coming home is extremely satisfying."
An elated Paine told the BBC: "I didn't think it would be this emotional. The amount of work that's gone into retaining the Ashes has been enormous and I'm really proud of this group and how we bounced back from Headingley."