WHEN Essendon's Peter Wright kicked seven goals in a round 21 win, the Western Bulldogs were missing injured full-back Alex Keath.

When Melbourne steamrolled Brisbane in the second half of a round 12 contest at Giants Stadium, it was Christian Petracca turning the tide.

What about Sydney's most recent win over Greater Western Sydney when players were left out at the last minute due to COVID-19 protocols?

History can be – but isn't always – a good judge of form, so AFL.com.au has gone back over the match-ups between this weekend's Toyota AFL Finals Series combatants to see what happened and what we can learn. 

Port Adelaide v Geelong

Round 13: Geelong 17.10 (112) d Port Adelaide 14.7 (91) 
This was the Jeremy Cameron Show. With the Cats trailing by nine points early in the final quarter, Cameron went to work, kicking three of his five goals to pilot his new team home. Tom Hawkins kicked four and Gary Rohan three as Port's defensive trio of Trent McKenzie, Tom Jonas and Aliir Aliir had real difficulty slowing them down. It's likely to be the same trio on Friday night, and what they've learnt from this encounter could go a long way to determining the outcome. At the other end, Connor Rozee kicked five goals, including four in a scintillating first quarter, as Zach Tuohy simply couldn't match the young Power star for speed. The home team was missing ruckman Scott Lycett on that Friday night, while Geelong opted for Esava Ratugolea over Rhys Stanley in the same position.

MATCHUP CATCHUP Relive the Power v Cats highlights on AFL On Demand

Jeremy Cameron celebrates a goal against Port Adelaide in round 13, 2021. Picture: AFL Photos

Sydney v Greater Western Sydney

Round five: Greater Western Sydney 9.17 (71) d Sydney 10.9 (69)
In many ways this was the match the got the Giants' season rolling, when they trailed by 21 points early in the final quarter before overcoming some goalkicking yips to sneak home. Toby Greene was the primary culprit for the missed shots, kicking 1.7, but his one goal came with three minutes remaining, shortly followed by Josh Kelly's winner. The only man that could stop Greene was himself. Lance Franklin kicked five goals in front of a strong SCG crowd, handing young Giant Sam Taylor a rare one-on-one defeat. GWS was missing Nick Haynes and Jesse Hogan, while the Swans were without Dane Rampe and Isaac Heeney.

Josh Kelly (right) celebrates his match-winning goal in GWS' win over Sydney in round five, 2021. Picture: AFL Photos

Round 18: Sydney 15.8 (98) d Greater Western Sydney 11.6 (72)
In a wild second instalment of the Sydney Derby, Lance Franklin again proved a handful, kicking four goals for the Swans. It's hard to know what to take from this match, though, as several players and staff from both clubs were forced to isolate less than an hour before the first bounce at Metricon Stadium in accordance with COVID-19 protocols. Callum Mills, Harry Cunningham and Colin O'Riordan (Sydney) and Toby Greene and Matt de Boer (GWS) were all late outs. The Giants led by 35 points during the second quarter, but a Sydney avalanche flipped the match on its head, as it kicked 12 of the final 14 goals. Tom Papley booted four from a mix of midfield and forward time. Greene's inclusion for Saturday's elimination final, and how the Swans handle him, will be a key to the result.

MATCHUP CATCHUP Relive the Swans v Giants highlights on AFL On Demand

Sydney's Tom Papley celebrates one of his four goals against GWS in round 18, 2021. Picture: AFL Photos

Melbourne v Brisbane

Round 12: Melbourne 14.13 (97) d Brisbane 11.9 (75)
This was the epitome of the footy cliché, "a game of two halves". Brisbane led by 20 at half-time and then Melbourne took control, kicking nine goals to three after the main break. Clayton Oliver and Christian Petracca got on top of the Lions' midfield that had regained Brownlow medallist Lachie Neale for the first time in six matches after he had undergone ankle surgery. Although the remainder of Neale's season has been stop-start with his body, he's likely to be cleaner and quicker when the teams meet again on Saturday night. Brisbane nullified the influence of Melbourne's intercepting defenders in the first half, but as the Demons' pressure ramped up, Steven May became more involved, and at the other end Tom McDonald and Kysaiah Pickett kicked three goals apiece. There'll be no Eric Hipwood to worry about for Melbourne's defence this time around either.

MATCHUP CATCHUP Relive the Demons v Lions highlights on AFL On Demand

Christian Petracca in action during Melbourne's win over Brisbane in round 12, 2021. Picture: AFL Photos

Western Bulldogs v Essendon

Round 21: Essendon 15.7 (97) d Western Bulldogs 12.12 (84)
Peter Wright came of age under the Marvel Stadium roof this day, kicking seven goals against a Bulldogs outfit missing full-back Alex Keath with a hamstring injury. Wright took advantage of his match-up with Josh Schache and rained balls from outside 50 to spark the upset win. Although the 203cm forward finished the job, it was the Bombers' midfield of Zach Merrett, Darcy Parish and some explosive centre clearances from Jake Stringer that helped turn the tide from an early three-goal deficit. The Bulldogs had 21 more inside 50s that day but could not take advantage, losing Josh Bruce in the final seconds to an ACL injury.

MATCHUP CATCHUP Relive the Bulldogs v Bombers highlights on AFL On Demand

Essendon's Peter Wright celebrates one of his seven goals against the Western Bulldogs in round 21, 2021. Picture: AFL Photos