Twenty20 international, Perth:
Sri Lanka 135-3 (16.3 ovs) bt Australia 133-8 (20 ovs) by seven wkts
Australia's revival was ended when Smith was stumped
Australia's troubles continued with a seven-wicket defeat against Sri Lanka in a one-off Twenty20 international.
After 2-0 defeats in both the Test and one-day series in India, they suffered their first home Twenty20 defeat.
Michael Clarke's team could only muster 133-8, but skipper Kumar Sangakkara struck 44 not out to guide Sri Lanka to victory with 21 balls left in Perth.
The Australians play three one-day internationals against Sri Lanka before the first Ashes Test on 25 November.
Australia had won all 10 of their home Twenty20 internationals dating back to 2006, but were in danger of recording their lowest total when they were reduced to 43-5 in the 11th over.
Steve Smith launched Thisara Perera over mid-wicket for six and shared a sixth-wicket stand of 66 with Brad Haddin, who lifted paceman Dilhara Fernando over long-on for six, before both departed within three balls in the 18th over.
Sri Lanka were always in control during their run chase after scoring 27 off their first three overs.
Tillakaratne Dilshan and Mahela Jayawardene put on 35 from 22 balls for the first wicket, before the latter edged a Peter Siddle delivery through to Haddin while on 24.
Dinesh Chandimal was given out lbw for two by umpire Bruce Oxenford, despite the ball from Dirk Nannes appearing to pitch well outside leg-stump.
The dismissals did not slow down Sri Lanka's run-rate, however, which was still at nine per over after five overs, pushing the required rate below six.
Dilshan was stumped by Haddin for 41 when Smith turned one past his bat as he charged down the wicket, but Perera ended the match in style with two sixes and a four in three balls off the leg-spinner.
"We have no excuses. I think we were outplayed tonight, as simple as that," said Clarke, who was booed by spectators at the post-match presentation. "We were just disappointing with the bat."