He said Australia can play much better than they did in Trent Bridge but very nearly won the match.
"A lot was covered up because England won, but they underestimated the Australian team, as many did and I believe Australia could win 2-1," the Australian wrote in his column in The Daily Telegraph.
Warne also took a jibe at Ian Botham for predicting a 10-0 scoreline in favour of England in back-to-back Ashes win.
"Some were arrogantly predicting that England would win the two Ashes series 10-0. Perhaps they are feeling a little concerned now," he commented.
The 43-year-old hinted at a lot of England problems and said Australia gained a lot more than England from the Test.
"Alastair Cook does not have full confidence in Steven Finn and Joe Root has not experienced the intensity of Ashes Test cricket and he will be feeling the heat a bit more after making 30 and five in the first Test. Jonny Bairstow has hardly played cricket recently and is looking for touch in an Ashes series," he added.
Australia had many positives from the Test and Warne listed some important ones and criticized the DRS which is acclaimed to be hundred percent accurate.
"Chris Rogers and Brad Haddin added steel. Phil Hughes played really well under pressure in the first innings. There is potential for so much more from the Australian side."
Praising 19-year-old debutant Ashton Agar, Warne said: "Ashton Agar’s performance showed the mood has changed in the dressing room. He handled the situation and pressure brilliantly. It showed a happy team environment where young players feel free to express themselves."
The highest wicket taker in the Ashes history suggested a few changes to the teams in their playing eleven for the next Test.
"James Faulkner and Usman Khawaja to replace Mitchell Starc and Ed Cowan for me, with Tim Bresnan coming in for Finn for England," he said.