Magpies forward Elliott kicked three crucial goals in his side's 13.14 (92) to 12.10 (82) victory at the MCG on Saturday.
But he landed awkwardly on his left knee late in the final quarter and crumpled to the turf in pain as trainers quickly called for a stretcher to take the 33-year-old off the field.
Elliott departed amid a melee as Collingwood players seemingly took exception to something that was said by one of their opponents.
Captain Darcy Moore (hamstring) and young forward Will Hayes (shoulder) were also casualties as the Magpies (5-5-1) climbed into a "wildcard'' spot with their first win since Anzac Day.
Until Elliott's injury, all eyes had been on 433-game veteran Pendlebury, who took the mantle as all-time games record-holder from retired North Melbourne legend Brent Harvey.
The 38-year-old star marked the milestone with 20 disposals and five clearances in front of 90,028 fans.
Even the margin was a fitting tribute to Pendlebury in his famous No.10 jumper.
Nick Daicos was best afield with 34 disposals, seven clearances and three goals, including a brilliant snap on the run that just about sealed the result moments before Elliott went down.
Jack Crisp (28 touches) and Jordan De Goey (26) were also influential, while Roan Steele and Dan McStay kicked two goals each.
Pies tall Darcy Cameron was involved in an absorbing ruck battle with Bailey Williams.
Tellingly, the Magpies won a lop-sided tackle count 77-46, which included 21 tackles inside-50 to three.
West Coast (3-8) were well served by Williams and young gun Harley Reid, who made his presence felt with 20 disposals in his 50th game.
Tom McCarthy (30 touches), Hamish Davis (23) and Milan Murdock (22) were all busy, and veteran Elliot Yeo kicked three goals.
Jobe Shanahan and Malakai Champion added two each.
After Harvey tossed the coin, Pendlebury started in the centre square and was the victim of an aggressive fend-off by Reid in the opening seconds.
But the veteran quickly levelled the scores, sending his much younger opponent over the boundary line minutes later with a strong bump.
The Eagles won an opening term for the first time this season, dominating the inside-50 count (19-11) and leading 3.2 to 2.6 at the first change.
There were nine lead changes in an arm-wrestle of a first half, before the Pies kicked the last two goals to create a 10-point buffer at the main break.
Daicos, who kicked a brilliant second-quarter goal on the outside of his boot at a stoppage, was central as the Pies burst 29 points clear in the third term.
He converted a controversial free-kick paid against Reuben Ginbey and delivered a clever tap-on in the build-up to  Elliott's stunning major moments later.
Elliott struck again to add the Pies' third goal in the space of four minutes.
West Coast looked gone but dug in bravely, kicking the next three goals to be within 11 by the final change.
Shanahan took a contested mark and converted to slash the margin to three points with more than seven minutes remaining.
But McStay used his strength on Williams and snapped a goal from a boundary throw-in and Daicos gave the Pies further breathing space with his third major.
