For that silent moment the ball was suspended in the air between KL Rahul's bat and Steve Smith at second slip, anything was possible.

The clock had only just ticked over to 9:50am and the umpire had barely called play when, with the first ball of the fourth morning, Pat Cummins found Rahul's edge.

Australia had arrived on Tuesday morning knowing it needed wickets, and fast. Rain was inevitably on its way and the only way to turn a dominant position into a win was going to be through another incisive bowling performance.

The ball floated toward the slips cordon, carrying with it Australian hopes of rapid acceleration, almost too good to be true.

And then Smith dropped it.

On a day when Australia needed absolutely everything to go right, something went immediately wrong.

Only Smith will know how he managed to spill the chance, though armchair analysis would suggest it simply came too early in the day for him, before he had fully switched his brain on to the task at hand. It's hard to come up with any other explanation.

The drop certainly didn't cost Australia the match as some have claimed, but it did cost them precious forward momentum on a day that would then tend towards the monotonous.

Rahul would go on to add a further 51 runs, but more importantly, would help to chew up another 25 overs. The 57.5 overs that Australia bowled on Tuesday was probably more than it had bargained for when glancing at the morning forecasts, but alongside Ravindra Jadeja, Rahul put an end to the home side's hopes for an avalanche of early wickets.

Compounding the Smith error was the sight of Josh Hazlewood, just six balls into his day's work, limping from the field with what turned out to be a calf injury.

Hazlewood missed the Adelaide Test with a side strain, was declared fit for Brisbane on the back of two weeks' heavy training and got through a spell on day three without concern.

But something went awry in the warm up on day four, and when he didn't take to the field for the first over of the day alarms were raised.

Hazlewood attempted an over, a suck it and see play to test out what was bothering him, and got his answer after his first, horribly wayward delivery.

It was a slow walk off the field for the rangy fast bowler, and later confirmation of a calf strain means it may well be his last act of the series.

He will almost certainly be replaced by Scott Boland in Melbourne, and given the burly Victorian's record on his home MCG patch that is no bad thing.

But Hazlewood is the preferred option in the bowling attack for a reason. He is obviously an incredibly consistent and reliable new ball bowler, but he is also more adaptable to different batters and different stages of the game.

When Rishabh Pant is charging and Jadeja is flaying, Hazlewood has more answers to those specific questions than Boland does. It's not a total disaster for Australia, but it is a blow.

But keeping things in the present, Hazlewood's absence is a killer here in Brisbane. Cummins and Mitchell Starc were suddenly tasked with an even greater workload with, at that point, 15 wickets still to take to force a result.

And when Australia turned to Nathan Lyon, it wasn't blown away with the result.

Lyon didn't bowl badly by any measure but was comfortably handled by the Indian middle-order, save for his wicket of Rahul — one which owed mostly to Smith's obscene make-amends catch at first slip.

Cummins bowled brilliantly all day and Starc enjoyed some threatening spells, but the day lacked juice from an Australian perspective as a result of India's dogged batting and yet more niggling rain.

Opportunity presented itself again late when Australia had the chance to finally wrap up India's first innings, but again the moment passed the hosts by.

An unbeaten 10th-wicket partnership of 39 between Jasprit Bumrah and Akash Deep took the game out of Australia's grasp, carrying their team beyond the follow-on to the delight of the Indian fans in the crowd who celebrated the runs as if they were the winning ones.

The Test is not dead yet, but it's on its last legs.

Australia now needs to come back on day five and take the final wicket, then smash the quickest 150-odd it can muster before somehow finding the time to take 10 more wickets.

The issue, as it has been since the first ball of this match, is the weather forecast.

There is a suggestion of more patchy rain from mid-morning and through the afternoon, with the prospect of another gnarly thunderstorm sprinkled on top.

Until the teams shake hands the Australians will continue to believe they can make something happen at the Gabba through sheer force of will. They've had to battle the elements as well as the opposition to get to this point, within reach of victory albeit with a mighty stretch.

Worst case scenario for Australia is a tied series going into Boxing Day. Throw back to late November in Perth and there wouldn't have been many Aussies who would have passed that opportunity up.

And yet it could have been so much more for Australia, had the weather been even slightly amicable and had day four not become such a series of unfortunate events.