Lomachenko (13-1) blew away Anthony Crolla to record his 10th professional knockout in the main event of a card on ESPN+ inside Staples Center in Los Angeles.
Lomachenko's profile has grown exponentially in recent years as he headlined at Madison Square Garden, in Macau and other Los Angeles-area venues before his step up to Staples. Referee Jack Reiss crouched down to count, but took a look at Crolla and immediately waved it off.
The writing was on the wall and within minutes Lomachenko wrote his final line with a pinpoint right hook.
"I want to fight with Mikey Garcia, but we'll see". However, it as in the fourth round where a perfectly executed right hand, landing right above Crolla's ear, sent the challenger face first to the canvas.
Two-time Olympic gold medallist Lomachenko improved to 13-1 with 10 knockouts. In the opening frame, Vasyl Lomachenko carefully gauges Anthony's movements with tricks and pressure.
Southpaw Vasiliy Lomachenko brutally knocked out former title holder Anthony Crolla in the fourth round Friday to retain his World Boxing Association and World Boxing Organization lightweight titles.More news: Wells Fargo's 1Q profits rise 14%, beating analyst forecasts
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Reiss ruled a knockdown late in Round 3 when combination punching from Lomachenko caused Crolla to sit down on the ropes while eating clean shots.
"He said: "I'm just so gutted for the team because of the work they did". "I [will] stay at 135 longer, it's possible".
Calling for an eventual showdown with his fellow star Mikey Garcia, fans of Loma will know that the bigger tests are still to come but for what it's worth, it was another polished display from the Ukranian.
Lomachenko has now won 12 straight bouts.
Karpency got in the ring with a black eye, and his nose was damaged early by Ramírez, the rangy puncher who had just one previous stoppage victory since 2014.