Marzocco became Godolphin's third qualifier for the £150,000 32Red Casino All-Weather Marathon Championships on All-Weather Championships Finals Day at Lingfield Park, Good Friday, April 3.
The John Gosden-trained galloper secured a hard-fought victory in the totepool Conditions Stakes over two miles on Polytrack at Chelmsford City on Thursday.
The four-year-old Marzocco, who finished fifth in the 2014 Group One Ladbrokes St Leger at Doncaster, returned the 4/9 favourite and was running for the first time since being gelded.
John Reel (David Evans/John Egan, 7/2) led the five runners along leaving the stalls with Marzocco travelling smoothly in second.
Marzocco took up the running approaching the final furlong and appeared set for an easy success but John Reel rallied gamely approaching the finish and Marzocco was forced to pull out all the stops to score by a neck. Fire Fighting (Mark Johnston/Joe Fanning, 8/1) finished third, a further three and a half lengths adrift.
Robert Havlin said: "Marzocco travelled a little bit too well on the first circuit. When I went past John Reel, I expected him to go clear but it is quite daunting for them coming up the straight.
"He had a good look at the stands and half dropped a gear with me, but when John Reel came to me he has picked up again. He is a good, strong traveller and maybe he just wants a bit of hanging on to. We have learnt a bit more about him today.
"He has got the trip well and, given the way he performed last year, he was always going to make up into a two-mile horse. He never got a chance to show that at Ascot because he got flattened. Hopefully, now he has been gelded and is a year stronger, he can show what he can do."
Godolphin now has three horses qualified for the £150,000 32Red Casino All-Weather Marathon Championships, with Anglophile (Charlie Appleby) and Hidden Gold (Saeed bin Suroor) having also taken Fast-Track Qualifiers.
