His response came after an appeal hearing decided to clear him to play in the decisive game.
Horwill will lead the Wallabies out at Sydney's ANZ Stadium in the concluding match of the series after the International Rugby Board's appeal against his alleged stamp on Wales second row Alun-Wyn Jones was dismissed.
The judgement of the original hearing nine days ago, during which it was determined that on the balance of probabilities there was no act of foul play, was upheld on Wednesday by independent appeal officer Graeme Mew.
A beaming Horwill, who revealed that he had been unable to sleep overnight while waiting for Mew's verdict which he received during a weights session, welcomed what he viewed as the correct outcome.
"I'm very relieved. The two hearings have been very fair. I found out about 10am (1am BST)," the 28-year-old lock said.
"I was confident because I know what happened and I'm glad the right result was made in the end.
"I love what I do and it means a hell of a lot to me to lead my country in what is probably the biggest game since the World Cup final in 2003.
"I'm very excited by the opportunity and now we can focus on the game, which is what's important. I feel very vindicated by the ruling.
"Other than not getting much sleep, it hasn't caused any disruption. I've just gone on with it, that's the reality of what we do."
Horwill stood on Jones' head in the third minute of Australia's 23-21 defeat in the first Test at Suncorp Stadium and the Lions forward subsequently required stitches in a wound above his eye.
A disciplinary hearing held 24 hours later determined that on the balance of probabilities there was no act of foul play.
The judgement was widely condemned and the IRB reacted by announcing on Thursday that following an extensive review of the case it would appeal.
After two and a half hours of discussions conducted by video conference, Mew retired to consider his the case and decided that only a major error during the original hearing would warrant the 'not guilty' verdict being overturned.
"For the appeal to succeed the IRB would have to establish that there was some misapprehension of law or principle by the judicial officer or that his decision was so clearly wrong or manifestly unreasonable that no judicial officer could have reached the conclusion that he did," Mew said.
"There was sufficient evidence upon which a reasonable judicial officer could have reached the decision that was made.
"Accordingly it could not be said that the judicial offer was manifestly wrong or that the interests of justice otherwise required his decision be overturned."
Mew also stated that the IRB's appeal had been properly taken in the discharge of its responsibilities to promote and ensure player welfare and to protect the image and the reputation of the game.
The IRB issued a statement accepting Mew's decision and maintained that lodging an appeal was the right course of action.
Horwill vigorously protested his innocence on the eve of the second Test, stating that the nine camera angles used during the original disciplinary hearing shed a different light on the incident.
When asked if the process had left a stain on his reputation, Horwill replied: "It's gone."
Australia coach Robbie Deans was satisfied by the outcome.
"The process was thorough, fair and just. That's what you seek on these occasions," he said.