Ernie Els and Phil Mickelson endured frustrating second rounds at the Scottish Open as the tournament’s headline acts were upstaged by some relative unknowns on Friday.

Chris Doak, ranked No.341 in the golfing world, was the surprise leader at the halfway stage of his home event after a second straight 66 left him on 12-under 132.

One stroke back, No.868 Matthew Southgate (64) was in a tie for second place with Ross Fisher (65), Peter Uihlein (66) and JB Hansen (65).

Conditions were ripe for low scoring on the Castle Stuart links but Els floundered on the greens and could only shoot a 2-under 70 to miss the cut a week before he defends his British Open title.

Mickelson, another four-time major winner, was joint third overnight after his first-round 66 but dropped back after a 70.