England A 135 for 2 (Scrivens 55*, Winfield-Hill 53*) trail Australia 285 (Mooney 107, Dean 3-49) by 149 runs
Mooney scored 107 from 133 balls at Leicester on Thursday, as Australia were all out for 284 and had their English rivals 2-135 in reply at stumps on day one.
With Meg Lanning out of the tour with illness and Rachael Haynes having retired since their last red-ball match, Australia gave their strongest indication yet of their line up for next week's Test in Nottingham.
Litchfield fell for 19, but still looks likely to earn a Test debut at the top of the order at Trent Bridge next week.
Mooney, however, had no such trouble ahead of the one-off Test against England that kicks off the multi-format series. She was dominant square of the wicket and punished an England A attack that was sometimes too wayward.
Mooney has opened previously in Test cricket, but has traditionally batted at No. 3 or in the middle order before Haynes' retirement. Her score was the only Australian one above 40, as others fell to loose shots around her.
"I seem to do that in warm-up games and not transfer that to the real thing," Mooney said. "Hopefully next week I can. The first few days in England it's nice to hit a few off the middle."
"Kimmy G is a ripper, she has contributed hugely to this group off the field and it's nice to see her getting some games on the field," said Mooney. She presents a real threat to the England top order, so it's nice to see her get a couple in this game."