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WATCH: All India's wickets on day three at the SCG
WATCH: All India's wickets on day three at the SCG

There were two key wickets Australia needed on the third day in Sydney. That Cheteshwar Pujara and Ajinkya Rahane both fell to Pat Cummins should be no shock in itself - he is the No. 1-ranked bowler in the world - but they were part of a masterclass in fast bowling that reinforced why Cummins has that tag and appears unlikely to let it slip without a fight.

Cummins' four main spells read: 6-3-10-0; 5-2-9-1; 6-3-5-1; 4-2-5-1 - no let up from start to finish. There was not so much as a no-ball or a wide. There might an inquisition over the three boundaries he conceded in the 21.4 overs: for the record they were through point and cover by Shubman Gill, who became Cummins' first wicket late on the second day, and a steer to third man by Pujara (the ball after taking a blow on the shoulder) against the second new ball.

However, it is considered a shock when Cummins does bowl a poor delivery. Today's performance was the most economical spell of at least 20 overs by an Australia bowler since 2014.

Back to the present day and ten overs into play on Saturday, Rahane, who had played the match-defining innings at the MCG with a magnificent 112, was cramped for room by a back-of-a-length delivery that nipped back and took a bottom edge into the stumps. But Cummins' best was still to come, 34 overs later.

Five balls after Pujara had done the rare thing of scoring a boundary, Cummins produced the ball of the day - perhaps the match - which climbed from a length and took the thumb of the glove through to the keeper. It was Australia's second wicket in five balls, following the removal of the dangerous but injured Rishabh Pant to end a 53-run stand that had taken India to 195 for 4. It was the moment where the Test took a likely decisive swing to the home side. The last six wickets fell for 49 runs.

It was also the cumulation of a contest that had spanned Pujara's 176 balls. This was no quick dissection, but in many ways that made it even more impressive. Australia, led by Cummins, held and squeezed until that little bit of magic came along. His career is already littered with such deliveries and there will be many more. His career average sits at 21.15, very close to the 21.08 he reached during the 2017-18 Ashes, and of bowlers to take more than 150 Test wickets only five have done it with a better average.

Cummins has now removed Pujara four times in the series. Here's how ESPNcricinfo's ball-ball commentary has recorded them:

2nd innings, Adelaide: Cummins is bringing Australia right back into this game. Superb delivery, angling into middle and off and straightening. Pujara absolutely has to play, the length is perfect. The feet don't go anywhere, and even though he plays as close to the body as possible, it moves just enough to take his edge and no more. His bat face is ever so slightly closed, suggesting he was playing the initial angle

1st innings, Melbourne: A brilliant delivery and an equally brilliant catch from Paine. Was a length ball angled in, making Pujara play. But as he looks to defend, the ball starts moving away, takes the outside edge and Paine, for a moment, looked like was wrong-footed. Does well to go low to his right and pouch it with his right hand. Cummins has changed the complexion of the game in his last two overs.

2nd innings, Melbourne: Edged and gone! Pujara pushes with hard hands into the gully. Uncharacteristic from him. This was full, not quite there for the drive, a hint of away movement with Pujara literally poking at the delivery half-heartedly. Australia have a second. Pujara kicks the turf, smashes the bat into the advertising triangles as he storms of fuming at the shot he's just played.

1st innings, Sydney: Jaffa and Pujara is caught behind. Back of a length, and he put some shoulder into that as he got it to bounce appreciably. Pujara has been so good at not letting his hands follow the ball but there was nothing much he could do about this. Tries to rise up with it to defend but the ball takes a thin edge off the shoulder of the bat and goes to Paine. Magnificent bowling by Cummins.

There have been subtle differences in each dismissal, but one thing that has not shifted is the unstinting accuracy around that off-stump channel. Pujara, because he is such a good player, has been able to repel and repel for significant periods (more than 400 balls now in the series) but unlike his herculean tour here two years ago, Australia have found a way to cut him off.

"The one today I think I got a bit of assistance with the pitch, it seemed to jump up a bit," Cummins said. "He is someone you know you are going to have to bowl a lot at. I think we got our head around that this series, for him to score runs we are going to make it as hard as possible."

Australia bided their time with Cummins, giving his body time to mature as the game champed at the bit for him to return, and that measured approach is reaping huge dividends.

"Hopefully a couple of years on, we are all little bit better equipped as bowlers and see what happens," he said ahead of the series when asked about the task of overcoming Pujara.

The series has not been decided yet and won't be until next week even if Australia win here, but if Tim Paine is holding the Border-Gavaskar Trophy aloft, Cummins will be a major reason why.

Andrew McGlashan is a deputy editor at ESPNcricinfo