No fewer than seven players became tied for the lead - and they included both Woods and Scot Paul Lawrie when each of them two-putted the long tenth for birdie.
South African George Coetzee found the most dramatic way to join them, though, sinking an eagle putt of nearly 30 feet at the 18th for a 65.
There were another six only one behind, McIlroy among them.
Hanson had a best-of-the-week 64 to set the clubhouse target of nine under, but Woods went into the lead on his own for the first time by holing from seven feet at the 12th and then over 20 feet on the 14th.
McIlroy had had seven pars in a row by then and found himself three back.
Woods was compiling an impressive round, but so was England's Robert Rock and when he matched the American's putt on the 14th they were both five under for the day and ten under for the tournament, a stroke ahead of Hanson, Olesen and Italian Francesco Molinari (66).
McIlroy broke his par run with a seven foot birdie putt on the short 15th and was two behind.
Woods had sole possession of top spot again when Rock failed to recover from driving into sand on the 16th, but the BMW Italian Open champion was back level with a five foot birdie putt on the next.
McIlroy also birdied there to be only one back, but that became two when Woods reached the green in two on the last and two-putted for birdie and a superb round of 66.