(CNN) -- South African Louis Oosthuizen set the clubhouse pace on the second day of the British Open at windswept St. Andrews after firing a five-under-par 67.
The 27-year-old, nicknamed "Shrek" by his close friends, was second overnight to leader Rory McIlroy, but made use of the kinder morning conditions to card a halfway total of 12-under 132.
This matches the lowest 36-hole total at the home of golf, set by eventual winner Nick Faldo and Greg Norman in 1990.
It gave him a five-shot lead over other early starters who had completed their second rounds, with former British Open champion Mark Calcavecchia on seven-under 137 and English hopefuls Lee Westwood and Paul Casey one shot behind at six-under.
