Hong Kong's 22-1 outsider Sky Field yesterday caused a big upset in the HK$24 million (S$4.2 million) Hong Kong Sprint, a race marred by a horrific four-horse fall.

The Lyle Hewitson-ridden rank outsider Amazing Star, who was up with the pace, went down at the home turn. This brought down the favourite Lucky Patch (Zac Purton), third fancy Pixie Knight (Yuichi Fukunaga) of Japan and fourth-backed Naboo Attack (Karis Teetan). Amazing Star was put down.

Hewitson, Fukunaga and Purton, who won the first three races, were taken to hospital.

Computer Patch led Amazing Star and Courier Wonder. Sky Field, trained by Caspar Fownes and ridden by Blake Shinn, was slightly further back than midfield. He was lucky to be spared from the unpleasant incident on Hong Kong's biggest meeting.

Courier Wonder kicked to the front but was collared by the fast-finishing Sky Field 150m out to win by three-quarters of a length in 1min 08.66sec.

He paid $110 in Singapore.

Japan's Resistencia beat Courier Wonder by half a length for second.