Looking up: An ecstatic Vasyl Lomachenko celebrates after winning his first professional fight

Thailand's Saensak Muangsurin is believed to hold the record for winning a world title in the fewest number of bouts at three when he won the light-welterweight belt in 1975.

More recently, Cuban Guillermo Rigondeaux won the interim bantamweight title in his seventh contest before going on to unify the division.

Opting to fight over 10 rounds on his debut in Las Vegas, Lomachenko faced a tough and game opponent in 25-year-old Ramirez who had lost just three of his 28 fights while stopping 15 of his 25 victims.

Technique: The Ukrainian goes on the defensive as Jose Ramirez fires in a right hand

But he was on the canvas in the first round as Lomachenko, whose purse for his debut was around £63,000, scored a knockdown with a left-right combination.

The Ukrainian was made to work hard for his successes however as his opponent, who had never previously been stopped, attempted to rough him up with pressure fighting.

But the debutante's speed was causing Ramirez no end of problems and his class continued to tell as the rounds progressed.

Quick start: Lomachenko knocked down Ramirez in the first round

He stepped up the pace in the fourth stanza, finishing the job with one second remaining as a sickening left hook to the body left Ramirez writhing on the canvas and unable to continue.

Lomachenko picked up the WBO International strap for his efforts, earning him the ranking to enable him to fight for the world title against three-time champion Orlando Salido in New York in January.

'It's my first fight as a professional and I wanted to give a good night,' he said. 'I had the power for him and I showed it.'

Left on the floor: Ramirez was no match for the Ukrainian