The Socceroos superstar was given his marching orders after the final whistle following an incident with Yohan Cabaye initiated by an alleged push on a ballboy
Cahill had come off the bench on 74 minutes for Everton before the late drama, when he appeared to grab the throat of the French midfielder.
The Australian had also gone close to scoring on 84 minutes, when his right-foot effort tested Magpies goalkeeper Tim Krul.
However, Cahill's day ended in controversy, when he appeared to grab Cabaye's throat with the pair exchanging words before a number of players became involved after the full-time whistle. Cahill would receive a red card for his part in it all.
Everton boss David Moyes told reporters: "I really don't know what it was about or what it was all for. I thought the referee could have shown a bit of common sense. He showed some common sense with [Chieck] Tiote, he had four fouls after his booking but I don't think he showed enough common sense with the Tim Cahill one."
It is understood the incident occurred after Cabaye pushed a ballboy, with Cahill incensed by the act.
Cahill wrote on Twitter after the game: "Overall it's been a roller coaster of season but finished on a High.2 all the blues out there THANKU for ur support this season."
In Germany's DFB-Pokal final on Saturday, young Aussie keeper Mitchell Langerak was plunged into the big game atmosphere as a 34th-minute substitute in Borussia Dortmund's 5-2 victory over Bayern Munich.
Langerak acquitted himself well enough after No.1 goalkeeper Roman Weidenfeller had to go off with a bruised rib.
The Australian entered the fray at 1-1, but Dortmund raced to a 3-1 lead by the break, before Langerak almost gifted Bayern a way back with a rush of blood as he raced off his line on 49 minutes.
But Langerak's headed clearance fell to Arjen Robben, who could not make him pay.
However, Langerak was fairly solid in goal, and could do nothing about Franck Ribery's fine left-foot strike on 76 minutes.
In Japan's J-League on Saturday, Alex Brosque made it five goals in all competitions this term with a last-gasp strike to earn Shimizu S-Pulse a 1-1 draw with Cerezo Osaka.
Brosque tapped the ball home from close range after 96 minutes - practically the last kick of the game - following a goalmouth scramble, with second-placed Shimizu desperate for a goal to keep them in touch with leaders Vegalta Sendai.
|STAR OF THE WEEKEND
Thrown in at the deep end in the German DFB-Pokal final but overcame his nerves and helped Dortmund lift another trophy
Vince Grella (Blackburn): Was an unused substitute as relegated Rovers ended the season with a 2-1 loss at Chelsea.
Sebastian Usai (Blackburn): The former North Queensland Fury goalkeeper was an unused substituted.
Chris Herd (Aston Villa): Started but was substituted off at the break after little impact and with his side trailing by two goals, in a 2-0 defeat to Norwich.
Brad Jones (Liverpool): Was an unused substitute in a 1-0 defeat away to Swansea.
Mark Schwarzer (Fulham): Played a full game as the Cottagers ended the campaign in ninth after a 2-0 loss at Tottenham. Schwarzer could do little about either goal.
Carl Valeri (Sassuolo): Was a 78th-minute in a scoreless draw away to struggling Livorno. The result was a missed opportunity for third-placed Sassuolo after the top two sides faced off over the weekend.
Luke Wilkshire (Dinamo Moscow): Absent from the side which drew 1-1 at Kuban Krasnodar on the final day of the season to finish fourth.
Ryan McGowan (Hearts): Had a tough afternoon, playing a full game, as the Jambos lost 5-0 to champions Celtic on the final day of the season, with Gary Hooper scoring all five goals.
Aaron Mooy (St Mirren): Wasn't in the Saints squad for the goalless draw away to Aberdeen.
Nathan Coe (SonderjyskE): Put in a full shift as his side blew a two-goal lead to draw 2-2 with FC Copenhagen.
Brent McGrath (Brondby): Not in the squad for the 5-1 loss away to AGF.
Scott Chipperfield (FC Basel): Out injured (groin) for the 6-3 win over Grasshoppers.
James Holland (Austria Vienna): Absent for the 1-0 triumph over Mattersburg.
Joshua Kennedy (Nagoya Grampus): Started and played 89 minutes, despite his recent back problem, as his side won 1-0 at Vissel Kobe.
Jade North (Consadole Sapporo): Put in a full shift in defence in the 1-0 home defeat to his former club FC Tokyo.
Matt Spiranovic (Urawa Reds): Wasn't in the squad for the 1-1 draw with Albirex Niigata.
Mark Milligan (JEF United): Was a 66th-minute substitute in the 6-1 victory away to Machida Zelvia.
Eddy Bosnar (Suwon Bluewings): Played a full game as the leaders eased to a 4-1 triumph over Gwangju.
Nathan Burns (Incheon United): Out injured for the 1-0 loss to Seongnam Ilhwa.
Robbie Cornthwaite (Chunnam Dragons): Put in a full shift in the 2-1 victory on the road to Sangju Sangmu.
Luke DeVere (Gyeongnam FC): Returned from a knee injury to play a full game as his side lost 1-0 to FC Seoul who scored a last-gasp winner through Dejan Damjanovic.
Matt McKay (Busan I'Park): Put in a full shift and provided another assist in the 2-0 home win over Daegu FC.
Adrian Madaschi (Jeju United): Played a full game in defence, but conceded a penalty for a push, in the 4-2 win over Gangwon FC.
Sasa Ognenovski (Seongnam Ilhwa): Put in a full shift in the 1-0 win over Incheon.
Matt Simon (Chunnam Dragons): Out injured (groin) for the 2-1 triumph at Sangju Sangmu.
Dino Djulbic (Shaanxi Chanba): Put in a full shift in defence as his side lost 2-1 away to Beijing Guoan.
Joel Griffiths (Shanghai Shenhua): Had to be replaced after 31 minutes due to injury in the goalless draw with Shanghai Shenxin.
Rostyn Griffiths (Guangzhou Fuli): Played a full game in the 2-1 victory over Henan Construction.
Mile Sterjovski (Dalian Aerbin): Put in a full shift where his free-kick led to the second goal in his side's 3-1 triumph away to Qingdao Jonoon.
Milan Susak (Tianjin Teda): Played a full game and popped up for a 70th-minute goal in his side's 2-0 win over Shandong Luneng. Susak headed home a deep cross at the back post where he was left unmarked.
Mark Bresciano (Al Nasr): His side won 5-3 over Emirates to move into second spot and shore up a 2013 AFC Champions League berth.
Lucas Neill (Al Jazira): Put in a full shift in the disappointing 3-2 loss to Al Wahda which dents their 2013 AFC Champions League aspirations as they slipped down to fourth.
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