It's no secret that Kawasaki had a four-cylinder 750cc four-stroke motorcycle on the stocks when Honda stunned the world in 1967 with the CB750 Four.
But the slide-rule samurai from Kawasaki are at their best under pressure, so they went back to the workshop and, five years later, they struck back with a motorcycle, and in particular its engine, that would found a dynasty which endures to this day.
Because the DNA of the 1972 Z1 is still clearly discernable in the Kawasaki's current litre-class musclebike, the Z1000.
The original Z1 had a 903cc, twin-cam, four-cylinder engine that was not only the most powerful of its time, it was as tough as nails, giving Kawasaki an enviable reputation for reliability.
By 1977 its capacity had grown to a full litre, and it had gained an angular 'coffin' fuel-tank, a sharp-edged handlebar fairing and a reputation for wayward handling that did nothing to diminish its mystique.
The 1978 Z1300 was an anomaly - it had six cylinders and liquid cooling - but it weighed more than 300kg, it was as indestructible as the air-cooled fours and had even more attitude - in fact it fell foul of the German 75kW rule and had to be detuned for that market.
The 1089cc GPz1100 was one of the first mass-produced bikes with electronic fuel-injection, as well as (for the time) revolutionary liquid-crystal displays for some of its instrumentation.
In 1981 Eddie Lawson won the AMA championship for Kawasaki on a factory Z1000S. The factory followed up with the Z1000R in 1982, still known as the 'Eddie Lawson Replica' and painted in Lawson's signature shamrock green, a colour that was to became synonymous with Kawasaki.
The Z was reborn as a naked street-bike in 2003 with the release of the Z1000, emphasising usable power rather than race-track performance, just like the original Z1.
It was revised in 2007 and almost completely reinvented in 2010, when for the first time, rather than borrow a previous-generation superbike frame, Kawasaki started from scratch in order to build a contemporary urban warrior that could live up to its engine - the legendary Z, 40 years old and still kicking ass.