Ernie Els opened up an eight-shot lead over Tiger Woods and Peter Lonard after shooting a six-under-par 66 in Saturday's third round of the USPGA Tour's Genuity Championship in Miami.

Els registered his first bogey of the tournament at the par-three ninth hole, but the two-time US Open champion from South Africa is on 17-under-par 199 after 54 holes at the Doral Resort and Spa course.

Barring a monumental collapse, Els is in position to capture his first title on American soil since the 2000 International.

Craig Parks, Vijay Singh, Justin Leonard and Rich Beem are tied for fourth at seven under, while Jesper Parnevik is one of three players at six under.

Seeking his first win of the year, Woods carded his second straight two-under 70 but lost four shots to Els. Lonard also carded a 70 after firing a 67 in Friday's second round.

Meanwhile, Tom Watson shot a three-under-par 69 to grab a two-stroke lead after the second round of the SBC Senior Classic in California.

The 1982 US Open winner collected five birdies against two bogeys on a day when Valencia yielded just three scores in the 60s.

He has a 36-hole total of three-under 141.

"On Thursday in the pro-am, I said this is the most difficult course we play on the Senior Tour," Watson said. "You have to play some US Open-type shots here."

Tom Kite is tied for second with Gil Morgan and Doug Johnson at one-under 143.

Christy O'Connor is tied for 15th place on 148 after adding a 75 to his opening 73.