Queensland need 154 from the final 25 overs to win their Ryobi One-Day Cup clash against South Australia on Sunday in Townsville.
Handy knocks from Tom Cooper (71 from 82 balls) and Dan Christian (100 off 90) have brought South Australia back into the match and a close finish is on the cards at Tony Ireland Stadium.
The home side was well on top until Christian hit a daring century that featured four huge sixes mixed with some clever shot selection and hard running between the wickets.
Cooper also looked brilliant at the crease and his innings included six fours and a six until he launched at a big drive straight down the throat of Reardon at deep cover in the first over left-armer Scott Walters' second spell.
Wicketkeeper Graeme Manou chipped in with a useful 20 from 21 balls as the Redbacks launched a late-innings charge.
Earlier the Bulls restricted the Redbacks to 4-88 in the first innings and then built a 13-run lead when they posted 2-101 from their 20 overs.
Paceman Cameron Gannon was the best off the Queensland bowlers with 3-68 from 12 overs while off-spinner Chris Simpson picked up with 1-45 from 10 overs.
Lee Carseldine (25 not out off 36 balls) and Chris Lynn (16 from 22) will resume batting for the Bulls.