Graeme McDowell after his birdie putt on the 4th hole during the third day of the WGC-HSBC Champions Golf tournament in Shanghai, on November 8, 2014 (AFP Photo/Johannes Eisele)

Shanghai (AFP) - Graeme McDowell lashed the snail-like pace of play Saturday at the WGC-HSBC Champions as "ridiculous" after a third round of one-under-par 71 reduced his lead to a single shot.

McDowell has led for all three days of the $8.5 million Shanghai event known as "Asia's Major", but he and playing partner Ian Poulter were angered by having to spend more than five and a half hours on the course in cold and damp conditions.

"Ridiculous," McDowell told AFP after finishing in near-darkness, having teed off at 10.50am (0250 GMT). Play ended in the gloom at 4.30pm, just a few minutes before sunset.

"We got to the fourth tee, the par three, and there was already a group on it," McDowell lamented.

"We've got threeballs, a lot of people out there and a couple of driveable par fours and a couple of two-shot par fives. Just a slow golf course. A long day," said McDowell, the 2010 US Open champion.

Ryder Cup star Poulter was less diplomatic in his assessment of the day after a level-par 72 left him four behind McDowell.

"There's no excuses. We need to be pressing and making sure people are keeping up to pace," Poulter told AFP.

"Five and a half hours is too long to play golf. End of story."

American Rickie Fowler, who finished in the top five in all four majors this year, was bewildered as to why the round took an hour longer than the first two days.

"Yeah, it was too long," Fowler told AFP.

"I'm not sure what it was. The first two days didn't take as long. We didn't have as many waits.

"Today was a bit cooler and the rough did play tough with the rain and the moisture. I guess it just shows you what a little bit of weather conditions can do."

The two major tours, the US PGA Tour and the European Tour, do have regulations governing slow play and can impose penalties, but it rarely happens.

The US PGA Tour last handed out a one-stroke penalty for slow play to 14-year-old amateur Guan Tianlang of China at the 2013 US Masters. It was the first such penalty on the Tour for 18 years.

Bubba Watson was the third member of the threeball with McDowell and Poulter Saturday and he has been a regular critic of the pace of play on the US PGA Tour.

And Watson knows what he would do to speed things up.

"You have to penalise people," he told reporters after the first three rounds at the Phoenix Open earlier this year took well in excess of five hours.

"Give them a stroke (penalty). It could cause you to win or lose. I think strokes is the only way to do it."