Daley, who has announced he will retire from Origin rugby league after this season, scored the decisive try late in the first half. The Blues protected a 12-8 half-time lead with no scoring in the second half.
Daley, playing his final Origin match in Sydney, also had more than 30 tackles including a try-saving effort on Gorden Tallis in the second half. "I've had so many great times in State of Origin and it's been a pleasure to play in it," Daley said. "I'm just bloody proud."
A crowd of 88,336 braved heavy rain to watch New South Wales tie the three-game series at Stadium Australia, the main arena for next year's Sydney Olympics. New South Wales scored after just 42 seconds when the Melbourne full-back Robbie Ross capped an 80-metre move with a try, and Ryan Girdler kicked the Blues to a 6-0 lead.
Mat Rogers, whose late drop goal gave Queensland a 9-8 win in the opening match two weeks ago, kicked an easy penalty on 18 minutes after the Blues were caught offside in defence. Rogers then added a try and a conversion seven minutes later to edge the Maroons ahead 8-6. Ross missed a tackle on Jason Smith, who was able to send Rogers across in the corner.
Daley put the Blues back in front on 34 minutes when he ran straight on to a well-timed pass from Andrew Johns and powered through. Girdler's conversion gave the Blues a 12-8 lead at the break.
The teams engaged in end-to-end attack in the second half but were unable to break through.
Matt Geyer crossed on 73 minutes but the referee, Steve Clark, called play back for a forward pass.
"The conditions suited our big forwards and what a great game it was," said the Blues prop Mark Carroll. "We're up there [Queensland] again in two weeks and we'll give it to them again."
The third match will be played in Queensland in a fortnight's time.
New South Wales: Tries Ross, Daley; Goals Girdler 2.
Queensland: Try Rogers; Goals Rogers 2.
New South Wales: Ross; MacDougall, Girdler, Hill, Geyer; Daley, Johns; Carroll, Toovey, Howe, Kosef, Fletcher, Fittler (capt). Substitutes used: Ricketson, Vella, Kennedy, Mundine.
Queensland: O'Davis; Rogers, Sing, D Smith, Sailor; Walters (capt), Green; Webcke, Hetherington, Greenhill, Tallis, McKenna, J Smith. Substitutes used: Ikin,Price, Carroll, Lang.
Referee: S Clarke.