"In the second half you could see that spirit was back, the boys really tried to turn things around.
"But it's a 2-2 draw and we have to live with that right now."
Australia had a woeful start to the match, sluggish and easily dispossessed by a well organised Oman until Cahill's goal after the break sparked the side into action.
The former Everton striker was a one-man show, brilliant in the air with several dangerous headers drawing superb saves from Oman's 'keeper Ali Al Habsi, who also had a stellar night.
It was a different story for Perth Glory defender Michael Thwaite who Osieck boldly partnered with with Robert Cornthwaite in the centre of defence in suspended skipper Lucas Neill's absence.
Thwaite was easily outpaced by Aziz in the opening minutes of the match, with the Omani striker silencing the 34,600-strong crowd at ANZ Stadium with his ensuing goal.
The result now puts pressure on Australia's next qualifier away to Japan in June.
"We have to display a better performance next time ... I definitely will have to consider who will be on the next trip to Japan," Osieck said.
"We have to get a result in Japan that's for sure."
James Holland was an other surprise starter, preferred to Mark Bresciano as Jedinak's holding midfield partner.
Bresciano came off the bench and made an instant impact only to suffer a knee injury after a short stint.
Oman coach Paul Le Guen while happy to get a point was left feeling his side had let a win slip through their fingers.
"It's quite a good result but when you lead 2-0 you expect more, you dream," he said.
He described Cahill as "one of the best players in the air".
"We were unable to compete in the air with Cahill ... he's very difficult to control," he said.
- AAP