Delta Blues beat his stablemate Pop Rock in a thrilling photo-finish to lead a Japanese one-two in Tuesday's 146th running of the Melbourne Cup.

The two horses, both trained by Katsuhiko Sumii, burst clear of the field down the final stretch to fight out the finish with Delta Blues holding on to win by half a head.

Maybe Better, ridden by Australia's Hong Kong-based jockey Chris Munce, fought on strongly to take third, four and a half lengths behind the runner-up, while Irish stayer Yeats was seventh and joint favourite Tawqeet 19th.

Delta Blues, who started at odds of 18-1, became the first Asian-trained horse to win Australia's richest and most famous horse race, first run in 1861, and only the third winner prepared outside of Australia and New Zealand.

The other two, Vintage Crop (1993) and Media Puzzle (2002), were both trained in Ireland by Dermott Weld.

Delta Blues, perfectly ridden by Yasunari Iwata, raced near the lead for the entire 3,200 metre journey but surged to the front rounding the final turn into the Flemington straight.

Pop Rock, ridden by Australia's Damien Oliver who won on Media Puzzle, was heavily backed in the last hour before the race to start as equal favourite at 6-1.

The six-year-old looked certain to win when he loomed up on Delta Blues in the final furlong but could not find a way past his stablemate.