Failing to read the local rules sheet cost PGA Tour golfer Ryuji Imada a whopping 26 penalty strokes at a tournament in China on Saturday, GolfChannel.com reported.

Imada wasn't the only golfer affected by a rules misunderstanding at the Mission Hills Star Trophy. Colin Montgomerie was penalized two shots after his caddie moved a sign on the 16th hole and finished two strokes behind tournament winner Lorena Ochoa.

Ochoa, the Mexican star who retired last year at the top of her game, shot a 71 in both rounds to earn the $1.28 million winner-take-all check at the 36-hole, mixed-field event.

Ochoa said the exhibition victory isn't enough to make her consider coming out of retirement. She said she's going to go back to Mexico "really happy."

Imada's 26-shot penalty came as a result of players being allowed to lift, clean and place their balls due to soft conditions on the Blackstone course.

Imada assumed he could place the ball within a club length of its original position, as is standard on the PGA Tour. But the local rules stated that placement had to occur within the length of one scorecard, as is standard on the Asian and European tours, according to GolfChannel.com.

Danny Lee pointed out the error to Imada on the 12th hole and at the end of the round, Imada informed tournament officials that he'd broken the scoring rule, according to the report. Imada couldn't remember exactly how many times he had given himself the more generous placement, but guessed he'd done so 13 times.

So Imada was assessed 13 two-stroke penalties, for a total of 26 penalty strokes and a first-round score of 24-over-par 97, according to the report.

Imada, who's 78th on the PGA Tour money list, has one career Tour win -- the 2008 AT&T Classic -- and four top-10 finishes this year. He had a solid October, tying for eighth at the Justin Timberlake Shriners Hospitals for Children Open and tying for sixth at the Frys.com Open.

But Imada acknowledged he failed to read the local rules sheet, GolfChannel.com reported.

"I'm an idiot," Imada said, according to the report.

He wasn't the only golfer who got stung by the local rules.

Montgomerie's tee shot on the 16th had landed a few yards behind an advertising sign on the fairway, which a marshal and Montgomerie's caddie, Jason Hempleman, moved out of the way, according to the report.

But tournament director David Parkin said players had been informed that under the local rules, the signs could not be moved. Since Hempleman had helped move the signs, Montgomerie was assessed a two-stroke penalty.

Candie Kung and Hong Kong celebrity Eric Tsang won the team competition.

The field included Greg Norman, Annika Sorenstam and Nick Faldo, along with celebrities Catherine Zeta-Jones, Hugh Grant, Michael Phelps and Matthew McConaughey.

Information from The Associated Press was used in this report.