Mackenna, bought by Sydney businessman Giorgio Alvaro for a reported six-figure sum last October, was a sensational Ladbrokes Golden Easter Egg heat winner on Saturday night in the second fastest time ever posted at Wentworth Park.
With caretaker NSW trainer Michelle Sultana deputising for Victorian conditioner Paul Abela, Mackenna began only fairly from box eight but was soon in front and won heat two by five lengths in 29.20.
After the race owner Giorgio Alvaro said: "I've raced dogs for 35 years and Mackenna is almost certainly the fastest I've owned.
"But whether she turns out the best remains to be seen because I owned Ben's Fury and he won the 2005 Group One Silver Chief final, and Mackenna hasn't won a group race for me yet.
"The day after I committed to buy Mackenna she came in season and the owner called me and asked me if I wanted to back out of the sale, because no money had changed hands at that stage.
"But I told him I still wanted her and I was pretty impressed tonight because Mackenna was having her first 520m test for six months.
"Her only race for me had been in a 450m race at Shepparton a month ago and she went super, winning easily in very fast time.
"After the Easter Egg series Mackenna will return to Paul Abela's kennels in Victoria.''
The second fastest heat winner on Saturday was August Bob, who led all the way in a personal best 29.35 for trainer and part-owner Steve Fitch and part-owner Paul Foreshew.
August Bob stunned racegoers by not only clocking such brilliant time but also by recording a sensational first split of 5.38.
Trainer Steve Fitch said later: "August Bob just keeps getting better and better and he is nailing the start now.
"His method is a bit unusual because he kicks against the back of the box after I put him in and then he seems to launch himself forward as the lids lift.
"It's a different way of jumping but I'm not complaining and I'm certainly not going to try and change it.''
Victorian trainer Tom Dailly won the 2013 Golden Easter Egg with Grigorieva Bale and two years later with Fernando Bale and he produced a powerful 2024 contender when SMOOTH PLANE stormed home from midfield to win his heat in 29.57.
Australian Cup winner Tim Zoo gave Jason Thompson, trainer of the 2016 final winner Moreira, a semi-finalist when he headed off Kangaroo Jack in the early stages to win his heat in 29.60.
Other heat winners were all NSW trained, Jack Smith's Irinka Daniel in 29.65, Shayne Stiff's Zali Keeping in 29.67, and Quantifiable for CHRIS O'Brien in 29.78.
The slowest winner was Zipping Megatron in 29.99, but the Jason Magri-trained dog's performance was exceptional.
After being slowly away from his unsuitable box seven draw, Zipping Megatron was checked but somehow found a rails run to be fourth on the back straight.
Zipping Megatron then collided with the hindquarters of pacemaker Taw Commander approaching the home bend before roaring home along the fence to win running away.
After the race trainer Jason Magri said: "For such a big dog he handles himself incredibly well in a field.''
Fellow trainer Minnie Finn said it all when she exclaimed: "Zipping Megatron races as if he had a jockey on his back!''
