While its contemporary namesake is a merely handsome four-door sport sedan, the original Maserati Ghibli stands, unquestionably, as the most beautiful car in the history of the House of the Trident. First shown as a two-seat concept car at the Turin Motor Show in November of 1966, the sleek fastback GT was penned by Giorgetto Giugiaro, then under the employ of Carrozzeria Ghia.

The Ghibli was a groundbreaking design at the time, and remains so today in the context of other 1960s-era landmarks like the DeTomaso Mangusta—itself a Giugiaro design unveiled in 1967—and the Lamborghini Miura, the first undisputed masterpiece by Bertone’s Marcello Gandini, which was also unveiled in 1966. Both of the designers were just 28 years of age when they established their respective legacies as the most important automotive visionaries from the last half of the 20th century.

The Ghibli went on sale in March of 1967, marketed as a 2+2 coupé, thanks to the addition of a rudimentary rear cushion. The model was Maserati’s grand statement, insofar as it was powered by a dual-overhead-cam V-8 engine that succeeded a venerable inline-six mill that was the mainstay of Maserati road cars since the first series-production 3500 GT of 1957.

The Sebring and Mistral followed—each of them exceptional cars—but the Quattroporte, which featured a V-8 engine derived from a real Maserati race car, was destined to power a GT worthy of the Trident. Enter the Ghibli. Named for a Mediterranean wind (many Maseratis are named after winds, from every corner of the globe), it really was something special. Powered by the marque’s 4.7-liter, dry-sump V-8 and developing more than 300 hp, it achieves a zero-to-60 mph time of about 6.8 seconds, imminently respectable for a GT of the day.

The upcoming Bonhams auction in Scottsdale, taking place at the Westin Kierland Resort & Spa on January 25, features a very special 1970 Maserati Ghibli. It is not a coupé, but rather, a convertible, and one of just 125 made. Chassis No. AM115/S/1185 is a numbers-matching example, and unlike the many Ghiblis equipped with a three-speed automatic transmission, this roadster came from the factory with a five-speed ZF manual gearbox. Significantly, it retains its hardtop, an especially rare accoutrement that most of the Ghibli Spyders do not possess. It also comes with a set of Borrani wire wheels in addition to the attractive alloys that it wears.

Altogether, 1,170 Ghibli coupés and 125 Ghibli Spyders (including 45 Spyder SS examples, carrying the 4.9-liter successor to the 4.7-liter V-8 engine) were made. Ghibli production ended in 1972, and the model was followed by the Maserati Khamsin designed by Marcello Gandini and named after a dry African wind. By that time, Giugiaro had launched Italdesign, and the rest, as they say, is history. This special Ghibli 4.7 Spyder is estimated to fetch as much as US$700,000 (HK$5,469,653).

Click here for more photos of this 1970 Maserati Ghibli 4.7 Spyder.