Cahill scored his 21st goal in just 42 appearances for Australia and his first at this tournament to give Australia a second half lead against Serbia but despite going on to win 2-1, the Socceroos missed out on a place in the last 16 on goal difference.
And that was despite finishing on exactly the same points - four - as they did four years ago in Germany when they beat Japan and drew with Croatia to reach the second round of football's biggest showpiece for the first time.
But in the end Australia's 4-0 loss to Germany in its opening game in Durban proved costly - as did the red card that Cahill received in that game - which ruled the country's best player out of the 1-1 draw with Ghana in Rustenburg.
However Cahill said the win over Serbia was the least Australia deserved for all the hard work it has put in during its time in South Africa.
"We were unlucky not beat Ghana and four points in a competition like this is exceptional and we were very unlucky not to go through (to the group stages)," he said.
However Cahill urged fans and the media to disregard the failure to reach the second round and instead focus on the positives of the campaign.
"The most special thing is we just beat Serbia 2-1 and it's a fantastic result," he said.
"It's about time the lads got some credit and the manager (Pim Verbeek) because to change the team the way he did (after the 4-0 loss to Germany in the opening game) and go for it was amazing and we fought to the end and showed we can beat any team."
"The positive thing is we won tonight (against Serbia) but to me sitting here (in the press conference) it feels as if you are guys (the media) are a bit down about it."
Cahill said he was delighted to make a big contribution against Serbia - with a trademark headed goal to give the Socceroos the lead - after the disappointment of being sent off against Germany and then suspended for the Ghana match.
"I was just so glad to play today and be part of this team and part of this nation," he said.
"To be sent off in such a big game (against Germany) has made me stronger as a person and as a footballer but as long as I am being a good example to the kids of Australia and the kids of the world by walking off and taking it on the chin then that is the main thing."
"The only way you can reply to setbacks like that is on the football pitch and it's the way you reply that counts and we did that together as a team tonight."
And while the ending of their campaign also signals the end of an era for the Socceroos with Scott Chipperfield and Craig Moore to retire and also possibly Mark Schwarzer and Harry Kewell - the only man to have ever scored for Australia at two successive World Cup Finals following his heroics four years ago in Germany has already set his sights on helping the Socceroos reach the 2014 World Cup in Brazil.
"For me I am one of the most passionate Australians," the 30-year-old Everton star said.
"I have played a lot of games for this country and put my body on the line and I give everything."
"So the only thing that will stop me (from continuing to play for Australia) is serious injuries or things like that but I am a very proud Australian and someone that will play on (for his country) as long as I can."