American Chez Reavie fired an eight-under-par 63 Thursday to upstage major champions Jordan Spieth and Jason Day in the first round of the PGA Tour Pebble Beach Pro-Am. Reavie fired an eagle and seven birdies with one bogey on the par-71 Monterey Peninsula course, one of three in use for the tournament along with Pebble Beach Golf Links and Spyglass Hill — both par-72 layouts. World No. 1 Spieth, winner of the Masters and US Open last year, opened with a one-under 71 at Spyglass Hill, as did reigning PGA Champion Day of Australia. "A bit weak," was Spieth's assessment of his round, which included four birdies and three bogeys. Spieth said a shaky short game led to setbacks on some of the course's easier holes. Nevertheless, Spieth said he wasn't discouraged, with the two courses he considers easier coming up in the rotation in an event in which pros play alongside celebrity amateurs in the opening rounds. Day teed off on 10 at Spyglass had three bogeys and two birdies in his first nine holes. He managed to get under par for the day with two birdies coming in. Sweden's Freddie Jacobson collected five birdies in one six-hole stretch at Pebble Beach and added two more for a seven under 65 and a share of second. He was joined at seven under by Australian Cameron Smith and American Bronson Burgoon, who both shot 64 at Monterey Peninsula. England's Justin Rose was among seven players at six under. Larsen leads in New Zealand Top-ranked Lydia Ko shot a 3-under 69 Friday and was three shots off the lead and in a tie for fifth place after the first round of the New Zealand Women's Open. The 18-year-old South Korean-born New Zealander, defending her national title, sank a 20-foot put on the 18th hole for the fifth birdie of an opening round which also included two bogeys and left her within reach of the lead held by Norway's Nicole Broch Larsen at Clearwater Golf Club. Larsen was a stroke ahead of Justine Dreher of France in the 54-hole tournament co-sanctioned by the Ladies European Tour. Gwladys Nocera of France and Scotland's Pamela Pretswell were tied for third, two behind Larsen, after 68s. Ko, who started her round with a birdie at the 10th, said she didn't fully exploit warm and calm conditions during her morning round, particularly on the greens. — Agencies