Lucia Valentina wins Gr 1 Queen Elizabeth

Lucia Valentina has produced a last-to-first finish to win the $4 million Queen Elizabeth Stakes at Randwick.

Going into Sydney's richest race on an abbreviated autumn campaign, Lucia Valentina was having only her second start since running in the Hong Kong Cup in December.

In what is a career-best run, Lucia Valentina ($8) overcame difficulties at the top of the straight to beat the favourite The United States ($4.60) with and Happy Clapper ($8) taking the minor placing.

It gave jockey Damien Oliver his third win for the meeting on Saturday and his second for Lucia Valentina's trainer Kris Lees.

Oliver said he had to ride his luck from the top of the straight after the mare was outpaced and settled at the tail of the field.

"She couldn't go with them at all early," Oliver said.

"But if you leave her alone she will reward you late."

Oliver took his chances to make his run between horses but he admitted the task might have been beyond Lucia Valentina.

"At the furlong (200 metres) (the race) was all over," he said.

"I went from the outhouse to the penthouse from the 400 (metres) to the 200 (metres)."

Happy Clapper had to be vetted after the Doncaster Mile runner-up became agitated in the barrier stalls.

Lucia Valentina banked $2.4 million for her victory, taking her career earnings to more than $6.5 million from seven wins in 27 starts.