His bid for the Italian title today will be dogged every step of the way by his old Walker Cup team-mate Dean Robertson, thanks to his own 68 which put him joint second. Only a three-putt on the final green prevented him sharing the Irishman's lead.
The two were members of the Great Britain and Ireland side demolished by a record 19-5 margin five years ago by an American side featuring Justin Leonard. Since then, 27-year-old Harrington has won the 1996 Spanish Open, but Robertson still seeks his maiden victory.
Harrington began the third round obviously fired up. He caught overnight leader Francisco Cea with two birdies in the first four holes, bogeyed the sixth as he pressed too hard, but was level again after a superb bunker shot on the long 12th, only to bogey the next as he tried to force the issue.
That was his last mistake, however. He holed from 20 feet for birdie at the long 15th and although Cea followed him in from 10 feet to stay ahead, the last two holes swung things around. First Cea was in two bunkers and horseshoed out from 10 feet, then he found more sand with his approach to the 18th and failed to get up and down again.
The big two - Jose Maria Olazabal and Lee Janzen - kissed goodbye to their chances. The Masters champion Olazabal, having birdied four of the first five holes, slipped to a 70 and six under alongside Seve Ballesteros, while the US Open champion Janzen managed only a 73 and is down at three under, 11 behind.Reuse content