Winner of last year's PGA Championship, belly putter user Bradley has been among several players under the spotlight since Wednesday's proposal by golf's rulemakers for a ban on putters being anchored to the body.
Though that ban would not come into effect until 2016 at the earliest, Bradley was criticised this week on Twitter before finally experiencing his first taste of heckling at Sherwood Country Club.
"I had some guy here call me a cheater on the last hole, which was no fun," Bradley said after firing a five-under-par 67 to end a day of intermittent drizzle two shots behind pacesetting Northern Irishman Graeme McDowell.
"But I look forward to hopefully making everything tomorrow with that belly putter and hopefully it (the criticism) will get a little louder.
"I never have (been heckled before). I've never heard anything negative. Today I heard a few things but I also heard way more positives than negatives."
Asked if he had responded to the fan on the 18th hole, Bradley replied: "No. You know, that's unfortunate. It's very disrespectful.
"But it's fine with me. I've got to try to look at it as motivation to help me try to win this tournament."
Bradley, who became the first player to win a major using a belly putter with his play-off victory over compatriot Jason Dufner at last year's PGA Championship, was delighted with his form on a soggy Saturday at Sherwood.
The 26-year-old, seeking his first tournament win since the WGC-Bridgestone Invitational in August, piled up six birdies and a lone bogey to finish the penultimate round of the 18-player event hosted by Tiger Woods at 11-under 205.
"I feel really good out there," said Bradley. "It's so fun to be back in the hunt again. It's been a while. It's been a few months, so it feels really good to be back out here in the heat of everything.
"Pepsi (Steve Hale), my caddie, gave me a little tip yesterday, and I putted better today, much better. I've missed a bunch of makeable putts this week, so hopefully they'll go in tomorrow."
Bradley, who needed only 26 putts on Saturday after totalling 33 in the opening round, relished the prospect of playing with 2010 champion McDowell in Sunday's final pairing.
"Graeme loves this place," said the three-times PGA Tour winner.
"He just has such an unbelievable record here. I'll be looking forward to playing with him tomorrow. It'll be a good time."
World Challenge leaderboard after third round:
203 Graeme McDowell (Northern Ireland) 69 66 68
205 Keegan Bradley (US) 69 69 67
208 Tiger Woods 70 69 69
Bo Van Pelt 70 68 70
209 Jim Furyk 69 69 71
210 Rickie Fowler 73 67 70
211 Nick Watney 67 73 71
212 Bubba Watson 71 74 67
Steve Stricker 73 71 68
Webb Simpson 70 73 69
214 Zach Johnson 74 70 70
Dustin Johnson 74 68 72
Matt Kuchar 73 69 72
215 Hunter Mahan 71 73 71
216 Ian Poulter (Britain) 73 72 71
Brandt Snedeker (US) 75 68 73
Jason Dufner 73 68 75
Jason Day (Australia) 71 75 72
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