The famous British outfit's slide from its race and title-winning days hit rock bottom in 2011, scoring just five points all season and only finishing ahead of the three struggling new teams in the constructors' championship.
But Oxfordshire based Williams has restructured for the 2012 season and is now led technically by former McLaren chief designer Mike Coughlan, and in Australia the newly Renault-powered FW34 qualified comfortably in Q3.
In the race, Pastor Maldonado was pushing Ferrari's Fernando Alonso for fifth place when he crashed heavily on the very last lap.
If he had made it round to the chequered flag, Williams would have scored more points in one hit than it managed all last season.
"The car was considerably better than anything I have seen in recent years," said team chairman Adam Parr.
Referring to Maldonado's crash, the team's new driver mentor Alex Wurz told Austrian ORF television: "Of course nobody is happy.
"The bad news is that we have to leave with no points, but the team has made a huge leap forwards."
Jaime Alguersuari, the former Toro Rosso driver turned radio co-commentator, called Williams' step compared to 2011 "giant".
"No doubt about it, Williams are the big surprise," the Spaniard told Mundo Deportivo when asked about the new field of 2012.
"Last year their car was really, really, really bad, and so they have taken an exceptional leap."