Lusail took his career record to three wins from four outings in the Tattersalls July Stakes at Newmarket.
Richard Hannon's two-year-old broke smartly for Pat Dobbs and led the main group down the centre, but Graham Lee was keen to get the rail on Project Dante.
When that rival began to weaken a furlong and a half from home, Lusail was left in front - but the race was just beginning in earnest.
Get racing news on your phone
Never miss a story with all the latest racing news, interviews and features on your phone. Find out more
Tom Dascombe's Sam Maximus, Alan King's previously unbeaten Asymmetric and Hugo Palmer's Ebro River all came to throw down a challenge - with the four in line at one point.
Ebro River was first to crack, not for the first time hanging badly, and Sam Maximus then began to tire.
There was not much in it as they crossed the line. But Lusail, who was emulating his sire Mehmas as a winner of this race, held off Asymmetric by a head - with the same back to Sam Maximus.
Hannon was confident, as Lusail passed the line, that he was in front. "I did think he'd won, actually," he said. "A trainer usually knows, and I think I've only got it wrong a couple of times.
"I thought he deserved to win - he ran around a bit going to the line."
Lusail was vindicating Hannon's judgement in reverting to this trip, after winning over a furlong further at Newmarket last month.
"It was a big shout to bring him back to six furlongs, but he's done it very well," the Marlborough trainer added.
"He's come back in trip - he's extremely relaxed, and I think we'll take him to Goodwood.
Follow Sky Sports Racing on Twitter
See the latest horse racing news, interviews and features from Sky Sports Racing
"Whether we go there for the six (Richmond Stakes) or the seven-furlong race (Vintage Stakes), we'll talk to the (owners) Al Shaqab team and see.
"He was just working okay in the spring. When I took him to York he hadn't really come in his coat, and I wasn't sure if I was doing the right thing, but he went there and won.
"He still looks like that now, but he's just like his sire Mehmas in that he's very honest and chilled out - and he will get further.
"I don't think he's just a two-year-old."