Hatton, who suffered a broken nose during a one-sided decision to Brook in March, floored Lomax with a right to the body which the former Prizefighter champion was unable to recover from.
'Magic' could now have another warm-up fight ahead of a world title showdown with IBO holder Chris van Heerden scheduled for next year in Cape Town.
"Even though I was confident, I felt I was a level above Lomax," Hatton told ifilmlondon.com. "I expected a tougher battle; he's quite awkward with a long reach, a south paw and obviously a Prizefighter winner.
"So to go in there and wipe him out in a round, I'm pleased. It was a shot I've been working on in the gym.
"I've got a fight scheduled supposedly for South Africa, but it's been put back to March, so there's a couple of things I need to sort out.
"But I'd like to fight again before Christmas," added Hatton, "I'm ready to go, so if I was offered a fight next week I would take it."