The win was the Swans' seventh of the season, placing them in 11th spot on the ladder.
Results on the weekend also were favourable for the Swans, with three sides battling for a top eight finish – Carlton, Essendon and Port Adelaide - all losing.
The in-form Swans midfielder says where there's a mathematical possibility, there's hope for a seventh consecutive finals appearance for the Bloods.
"After last week's performance (a loss to Carlton), I suppose everyone wrote us off. But to have a win and have a few results go our way has got the boys up a bit. The possibility is still real, so I suppose everyone's getting excited," O'Keefe said on Monday.
"Ten wins will probably get you in the finals this year. I suppose our percentages aren't as strong as the others, but if we get a few more wins on the board, who knows?"
Coach Paul Roos has publicly played down talk of a seventh consecutive finals appearance. The Swans' percentage (91.18) is weaker than every team ahead of them except Port Adelaide (90.90), while the Swans have a tough run home, facing Collingwood in Melbourne and Geelong, Brisbane and St Kilda at home in the final five weeks.
The ladder-leading Saints play in Sydney on Saturday, and while Ross Lyon's side is a clear favourite to extend their 17-match unbeaten run, O'Keefe said the Swans can take heart from a similar scenario five years ago when the two sides met.
"In 2004, St Kilda won 12 or 13 in a row and came up here and we beat them. So we've done it before," O'Keefe said.
"We're going out to win, that's for sure. We're not here to muck about. You hear about development, but the only way to help these (young) guys improve is getting into winning habits."
While that's easier said than done, O'Keefe believes the Swans' traditional style of play over four quarters is the key to stopping the Saints.
"We're not going to lower our standards win, lose or draw," said O'Keefe, who picked up 25 possessions at Manuka on Sunday.
"We're just going to have to match them in that hardness and that pressure around the ground and keep it for four quarters.
"They've been able to do that, and that's why they keep winning."
