(CNN) -- Tiger Woods will take a one-shot lead into the final round of the Arnold Palmer Invitational at Bay Hill bidding for his first PGA Tour victory since September 2009.
Woods shot a one-under 71 Saturday for a three round total of 11-under 205 with Graeme McDowell of Northern Ireland his nearest challenger.
2010 U.S. Open champion McDowell also carded a 71 in testing conditions in Florida, but has been given encouragement by late slip ups by Woods.
The six-time Bay Hill champion looked set to hold a big lead going into the last round as he led McDowell by four shots with five holes to go.
But a bogey on the 14th and a double bogey on the next, the apparent victim of noise from the gallery as he drove out of bounds, saw his advantage disappear.
McDowell finally made a birdie after a run of straight pars to draw level, but Woods birdied the long 16th and parred home to maintain a slender lead.
South African veteran Ernie Els shot a best of the day 67 to go into a tie for third at eight under with England's Ian Poulter, who carded a battling 68.
Els has to finish in third to have a chance of moving back into the world's top 50 and getting an invite to the U.S. Masters.
McDowell will be hoping for a repeat of his win at the invitational Chevron World Challenge in 2010 when he came back from four shots behind to beat last-day partner Woods.
14-time grand slam champion Woods won the 2011 edition of the World Challenge tournament he hosts but is still searching for a comeback win in a full-field event.
He holds a 37-2 lead going into the final round of PGA Tour events.