On the one hand there was Kristin Armstrong, hoping to complete a fairytale return to road cycling with a third consecutive Olympic time trial gold the day before her 43rd birthday.
On the other there was Olga Zabelinskaya, a Russian rider with a doping past who was nearly booted out of the Games.
So when Armstrong, the last of the field to tackle the 29.7km course on a wild and wet day next to the Atlantic breakers, crossed the finish line five seconds quicker than Zabelinskaya had managed it felt fitting in so many ways.
Not only had Armstrong become the first rider to win the same road event at three different Olympics - providing a fillip for all 40 somethings to boot - she also spared the Games what would have been a controversial victory.
Double London medallist Zabelinskaya, who served an 18-month suspension for a banned stimulant and who got a last-gasp reprieve to compete after the IOC's attempt to ban Russia's previous dopers collapsed, had looked poised for victory.
She was almost celebrating at the finish, only to watch Armstrong, pedalling like fury, roar home in 44 minutes 26.42 seconds before collapsing on to the tarmac in exhaustion.
Dutch rider Anna van der Breggen confirmed her reputation as women's cycling's new force by adding a bronze medal to the gold she took in Sunday's road race, finishing 11 seconds back.
But the day belonged to Armstrong.
She retired in 2009 to start a family but returned to win gold in London before calling it a day again. After a three-year break and three hip surgeries she made another comeback last year with an eye on Rio.
No wonder she cried with joy at the finish where she cuddled her son Lucas, who she later admitted had preferred watching the fencing because he thought it looked like Star Wars.
"It's amazing, I don't know if it has hit me yet," Armstrong told reporters after hugging her five-year-old son and holding up a sign that said "USA STRONG".
"This has been the most difficult journey. I took time off. The mind gets tired. So when I came back I was focused on Rio and it's been difficult because I've had some poor performances over the last six months."
The race was run in treacherous conditions but thankfully there were none of the accidents that marred the road race although former world champion Ellen van Dijk fell into the roadside foliage when riding uphill.
Armstrong used all her vast experience to tackle two tough climbs and stayed calm as the seconds ticked away on the run-in.
