She got it done in the 80th minute, tapping in a rebound to lead Australia to a 1-0 win over Brazil 1-0 to advance to the quarter-finals of the FIFA Women's World Cup.
A well placed ball from substitute Katrina Gorry found Lisa De Vanna charging down the right side of the field. De Vanna's shot was blocked by Brazilian goalkeeper Luciana, but the rebound went right to Simon, who scored the first goal conceded by Brazil in the tournament.
"All that was going through my head was to be there in case (the goalkeeper) fumbled it," said Simon, who had been substituted into the game just 16 minutes before the goal. "It just so happened that the ball fell at my feet and I got the tap-in."
It was also a bit of deja-vu for the Aussie, who scored her very first international goal against another team from Brazil.
"It kind of brought back flashbacks," she said. "I was only 16 years at that age, and it was kind of ironic going on the field. I fell back to that moment and felt what an amazing moment it would be if I could do that again."
There was no scoring in the first 45 minutes despite aggressive play from both teams.
At 14 minutes Caitlin Foord of Australia made a solo drive towards the net but was stopped at midfield by Brazil's Fabiana, who drew a yellow card.
The best chance before half came at the 28th minute, when Brazil's Formiga launched a booming shot from outside the box on target for the top, right-hand side of the net, but it was deflected up and over by Australian goalkeeper Lydia Williams.
Australia's goalkeeper was forced to make stops on shots by Cristiane and Marta at 62 minutes, while the post stopped a shot by Formiga a minute later.
The Australians counter-attacked quickly, but a shot from Emily Van Egmond was blocked.
Williams made a big save at the 90-minute mark off a header from Cristiane to preserve the lead.
Australian coach, Alen Stajcic called the win "exhilarating," and said he felt good with his team's attacking style.
"I think we're one of the most dangerous teams at the World Cup if not the most dangerous team in going forward," he said.
Stajcic, however, was quick to stress there are more games to be played, and he believes the team's biggest moment is yet to come.
Brazil coach Vadao congratulated Australia on the win. He said his squad was very competitive and had nothing to be sorry about.
"The only thing that went bad was we didn't score a goal," he said.
Australia moves on to Edmonton, where they will play the winner of Tuesday's game in Vancouver between Japan and the Netherlands.
The game in Moncton was marked by cool temperatures and rain. Most of the crowd of 12,054 came prepared with rain gear.