Highly underrated sprinter Aussie Rocks proved an unsuspecting ‘rock star’ with an upset victory in the $1,008,000 Group 1 Sportsbet Melbourne Cup final (515m) at Sandown Park on Saturday night.

In winning the sport's 'Holy Grail', he joined an honour roll dripping with history – virtually reducing veteran Spotswood trainer Geoff Mitchell, 68, to tears.

Practically lost for words, Mitchell uttered: "Unbelievable… What's happened now, you tell me.

"I can't believe it. He's the best dog I've ever trained. I've trained dogs for 45 years."

In reference to one of Aussie Rocks' owners, Mitchell said: "He'll be crying up there (in the Henry Harrison Grandstand).

"This is what you get up and train dogs for," Mitchell added. "It's just one of those things, it's hard to explain."

Aussie Rocks ($16.40) landed a cool $650,000 first prize with a proverbial 'rails like a greyhound' performance. He defeated a gallant Big Energy ($1.90F) by 0.4L, with Mac's Damage ($19.30) a further 0.6L away third in 29.55sec.

Runner-up in this year's G1 National Sprint Championship, Aussie Rocks notched his 16th win from 37 starts. His stakes spiralled to $767,935. He was also a finalist in this year's G3 Silver Bullet.

It was also a sensational result for stud dog Aussie Infrared which sired the quinella.

Since the Melbourne Cup's inception in 1956, Aussie Rocks is only the seventh greyhound to win the race from Box 5. And he's the longest-priced winner in the past 20 years.

Meanwhile, NSW staying monarch Palawa King reigned supreme in the $165,500 Group 1 Sportsbet Bold Trease final (715m).

Trained by Ray Smith, Palawa King did it the hard way, working through the field after 'falling out' at box rise.

Palawa King ($6.00) notched his 22nd win from 53 starts defeating counterpart Ritza Piper ($10.30) by 1.3L with Victorian champ Zoha Bale ($2.90F) a further 0.2L away third in 41.75sec – only 3L off the 41.57sec race record, set by Sweet It Is in 2014.

And for the second successive year, NSW quinellaed the race. Last year, Stagger Out Lee defeated Cawbourne Magic.

The $105,000 first prize catapulted Palawa King's prizemoney to $656,905. It was his third G1 victory, having also taken out this year's Queensland Cup at Albion Park and National Distance Championship at The Meadows.

"He went nice," a humble Smith said. "We knew he was a run short (in the heats).

"It's one off the 'bucket list'; I hadn't won a Group race here (at Sandown).

"He's got a big motor. When we get the preparation right, he's hard to beat."