Spieth sets Masters pace again, Day and Bubba ominously placed

Tied second and first respectively on his two previous Masters appearances, Spieth excelled once again at a venue where he has never been over par, emphatically answering any doubts about a dip in form.

Jordan Spieth takes the plaudits after a birdie at Augusta.

Jordan Spieth's love affair with Augusta resumed on Thursday as the reigning champion laid down a marker to his Masters rivals by claiming the early clubhouse lead with a superb opening round of 66.

Tied second and first respectively on his two previous Masters appearances, Spieth excelled once again at a venue where he has never been over par, emphatically answering any doubts about whether he was ready to contend this week following a dip in form.

The 22-year-old Texan started with a 64 on his way to a wire-to-wire victory 12 months ago and, although he was unable to match that score this time around, his six-under total represented a fine effort as moderate winds swirled around Augusta.

When he putted out on the 18th, Spieth led by three shots, but two of the other favourites for the competition - Jason Day and Bubba Watson - were among his nearest rivals at three under with more than half of their rounds to complete. World number one Day eagled the par-five second and picked up another shot at the fifth, while Watson - the Masters champion in 2012 and 2014 - birdied the first, seventh and eighth.

Also at three under were Paul Casey, one of Spieth's playing partners, Justin Rose (through 13 holes) and Shane Lowry (through four), while Rory McIlroy was level par after four in the final group.

Spieth first claimed sole possession of the lead at the eighth, courtesy of his third birdie of the day, and held a two-shot advantage after following up another gain at the 10th with a superb par save on the next. Two more clutch par putts dropped at 12 and 14, either side of a fifth gain, and Spieth again got out of trouble at the 16th - producing a wonderful up-and-down to keep a bogey off his card.

A precise approach to 18 then set up another birdie chance, which was clinically converted.

While Spieth had much to celebrate, Rickie Fowler endured a miserable opening round. After bouncing back from a double bogey at the first with three birdies in four holes, he lost his way once again and carded an eight at the 13th on his way to a damaging 80.

There was an even worse start for four-time major champion Ernie Els, who took seven putts from short range on the opening hole to run up a shocking 10.