Ernie Els played so badly last week that he went back to basics in an effort to find some form. Oh what a difference a week makes.

Hard work on the range paid almost instant dividends as Els charged into the lead after the second round of the 8.5 million-dollar World Golf Championships CA Championship on Friday.

The South African carded a bogey-free 66 for a 10-under-par 134 total after 36 holes, one stroke ahead of Australian Robert Allenby on a day of fluctuating weather.

American Bill Haas and first-round leader Charl Schwartzel of South Africa were equal third, three strokes behind, while defending champion Phil Mickelson remained within striking distance, six shots adrift after a 68.

"I didn’t have it last week (at the US PGA Honda Classic), so I worked really hard Saturday, Sunday, Monday, Tuesday and Wednesday," said Els, who adjusted his posture, alignment and ball position.

"I did find something, so I’m sticking with it. By Wednesday it started feeling a bit more comfortable and now I feel I can hit the ball with more authority and keep the ball flight down."

Finding his form a month before the Masters, an event he has never won, Els revealed he was working again with swing coach Butch Harmon, the former instructor of world number one Tiger Woods.

"After playing professional golf for 20 years, you should figure your own swing out by now," Els said. "I just reconfirmed with Butch what I was doing and he agrees.

"We'll probably work together a little bit this year but it’s basically the same stuff we worked on when I totally lost it two years ago."

Els, who won here in 2002 when Doral hosted a PGA event, was speaking after a round that started in a warm southerly breeze that switched almost 180 degrees in a matter of seconds around noon.

Els was on the fourth tee when the change occurred.

"I’m just about to pull the club back and I feel this chill come over me," he said. "The wind changed right there and then it was blowing out of the north."

Intermittent thunderstorms subsequently caused two suspensions of play, although Els had finished by then.

Allenby, for one, was not happy officials took so long to stop play. He was on his final green when a rain squall swept through.

"It started hosing down and blowing about 30 (mph)," said Allenby, who three-putted after his first putt came up seven feet short.

Earlier, Allenby made a hole-in-one at the par-three 13th with a five-wood from 232 yards.

"It landed perfect, about 15 feet short of the hole, and then sort of checked up and rolled up into the hole," said Allenby, who joked that his sparse gallery of "four" spectators enjoyed the moment.

Allenby also eagled the par-five first and had six birdies, but he threw in three bogeys and a double bogey in a topsy-turvy 67.