Imperatriz has added a second win in the William Reid Stakes to her growing total of Group 1 wins.
Imperatriz kept her unbeaten record at Moonee Valley intact when claiming a second win in the William Reid Stakes.
It prompted the mare's trainer Mark Walker to wish all Group 1 races were run at Moonee Valley.
Imperatriz is a three-time winner at Group 1 level over Saturday's 1200m course having also won the Manikato Stakes last spring while also being the victor of the Moir Stakes (1000m).
Sent out the $1.70 favourite under Opie Bosson, Imperatriz held off outsider Johnny Rocker ($71) by a short neck with I Am Me ($6.50) a further two lengths away third.
Imperatriz has raced in Melbourne on eight occasions, registering seven wins, of which six have come at Group 1 level.
Her solo defeat came in the Newmarket Handicap (1200m) when Imperatriz was burdened with topweight of 58kg and was far better placed under Saturday's weight-for-age conditions.
"It's a great thrill, especially after the Newmarket," Walker said.
"She really dug deep that day and to come back here and do it at her favourite track, it is a bit of relief, really.
"She got into a nice spot, and we haven't had much luck today on the fence, so I knew we'd be out from the draw.
"It was great to come back from the Newmarket (and win), because that was a tough run and to show her fighting qualities today was brilliant.
"She's extremely good and I'm thankful that she's in the stable."
Bosson, who flies in from New Zealand to ride the mare, said after Imperatriz had been beaten in the Newmarket Handicap that she would be hard to beat at weight-for-age from that point forward.
He was proven correct, although Imperatriz had to make a longer run that he had hoped.
"I seemed to get in quite nicely behind Bella Nipotina and I thought she'd take me into the race, but she didn't," Bosson said.
"I had to make quite a long run, to be fair to her, down the side and when we turned in and she gets on that right leg going down the straight she is amazing.
"You can feel her picking up underneath you and once she balances up, she is all class.
"I'm glad she came out there and won the way she did."