Anyone fancy either to win? Or will the winner come from the hunting pack?
Fleetwood shares halfway lead for second week running as McIlroy stages thrilling finish to day two in Florida.
Fleetwood enjoyed a "dream start" with two birdies and an eagle over the first three holes, and his fifth birdie of the day at the last capped a 67 which got him to 12 under, a target that was soon matched when McIlroy produced a sparkling finish to his 65.
After four birdies in five holes around the turn, McIlroy made a superb eagle at 16 and holed a lengthy putt for a bonus birdie on the 17th green before narrowly missing out on the outright lead at the last following a remarkable second from the pine straw.
The leaders are three clear of their closest challengers, a group which includes 2017 runner-up Poulter after he chipped in twice in three holes during his 66, while veteran Jim Furyk posted the round of the day with a serene 64 which gave him the early clubhouse lead on nine under par.
Fleetwood birdied the first and third either side of a thrilling hole-out from a greenside bunker for eagle at the second, and he bounced back from his first blemish of the week at the ninth with two further birdies over the next three holes.
The 28-year-old endured a scrappy spell down the stretch and dropped another shot at 15, but he safely negotiated the 17th and finished on a high with a 10-foot putt for birdie at the last. While he went to the media centre for his press conference, with many confident he would have the outright lead at the end of the day, McIlroy suddenly propelled himself into a tie at the top after another round of consistent driving, solid iron play and precise putting.
A bogey at the first was quickly atoned for as he got the shot back at the next, but he remained on five under until reigniting his challenge with birdies at eight, nine and 10, although he missed out on four in a row after a misread from eight feet at the 11th.
But he picked up a bonus birdie from 25 feet at 12, and a towering 224-yard second to inside 10 feet at the long 16th was converted for eagle, and McIlroy then found himself tied at the top thanks to another assured putt on the 17th green.
His aggressive drive at the last leaked into the pine straw to the right of the fairway and his path to the green was blocked by the trees, but he fashioned a delightful high fade with a wedge to inside 20 feet, and he settled for a two-putt par to complete a fine day's work.
Furyk, who turns 49 in May, made the most of the benign, early conditions and made four birdies on each nine while keeping a bogey off his card, while Brian Harman (69) and Abraham Ancer (66) joined the share of third place alongside an inspired Poulter.
The Ryder Cup legend started at 10 and birdied two of his first three holes before giving both shots back when he pulled his tee shot into the drink at 13, but he chipped in for eagle at 16 and for birdie at 18 before keeping his momentum flowing with four birdies in five holes - a run he capped with a 40-foot putt at the fifth. Poulter lost a little ground on the leaders when he closed with a disappointing six at the ninth, but he had done enough to earn a place in Saturday's penultimate group with Furyk, while 2016 champion Jason Day proved he was over the back problem that forced him to withdraw after six holes last week as he raced to eight under with a 66.
World No 1 Dustin Johnson and Spaniard Jon Rahm both carded 68s to move into striking range on seven under, with Scotland's Russell Knox and reigning Masters champion Patrick Reed one stroke further off the pace. Justin Rose's hopes of regaining top spot in the world rankings were revived as he recovered from his opening 74 with a spirited 66 which included a spectacular eagle-two from 152-yards at the 15th, while Tiger Woods was left to rue two costly mistakes at the 17th as a 71 left him with nine shots to make up.
Woods had cruised to three under for the day after six holes, and five under for the tournament, and with his all-round game looking in fine fettle until he donated two balls to the lake around the 17th green. The two-time champion found dry land with his third attempt and two-putted for a quadruple-bogey seven that left him flirting with the cut, although he dug deep over the front nine and birdied the second and seventh to make it safely through to the weekend.