ORLANDO, US - WORLD number one Tiger Woods joined four opponents in first place at the Arnold Palmer Invitational after a four-under par round of 66 on Saturday.

Woods, looking for his ninth win in 10 tournaments, began the day seven shots off the lead but ended on six under-par with in-form Sean O'Hair, winner at Tampa Bay last week, who fired the best round of the tournament with his seven-under 63.

Bart Bryant produced his third consecutive two-under 68 to join the leading pack along with Bubba Watson and overnight leader and defending champion Vijay Singh.

Singh, who began the day on nine-under, had an eventful round with two bogeys and a double bogey inside his first seven holes but he recovered slightly to finish with a three-over 73.

Hunter Mahan was a shot behind the leaders and then five players, including Nick Watney who had led before a quadruple bogey on the 16th and Britain's Lee Westwood, were two off the lead on 206. -- REUTERS