Adrian Otaegui made an early statement of intent at the Scottish Championship, defying the chilly, autumnal conditions at Fairmont St Andrews to claim a three-shot lead after the opening round.
The Spaniard carded a blemish-free 62, knocking in 10 birdies to leave the chasing pack in his wake.
England's Matt Wallace and South Africa's Bryce Easton are tied for second.
Zach Murray returned the best round from the Australians in the field with a three-under 69.
Ireland's Padraig Harrington and English trio Chris Paisley, Aaron Rai and Garrick Porteous each carded six-under 66s, with compatriot Lee Westwood among a cluster of players a shot further back.