North Berwick's Catriona Matthew made her best start to the season with a four under par 68 that placed her just one stroke off the lead after the first round of the Sybase Classic at New Clifton in New Jersey.

The Scottish No.1 birdied the 18th to finish in a tie for fourth place and just a shot behind the trio of Annika Sorenstam , South Korea's Song-Hee Kim and Australia's eight-time Tour winner, Rachel Hetherington.

Matthew was in a group of six that included world No.1 Lorena Ochoa, while Glasgow's Janice Moodie, the only other Scot in the line-up, was down the field on four over par 76.

Just days after announcing that she would retire at the end of this season, Sweden's Sorenstam had a faultless round. She birdied the second and added more at the fifth and seventh in an outward half of 33. She then picked up more shots at the 11th and 14th.

Ochoa, who has won five times this year, began her defence of the title with five birdies. The 26-year-old also dropped a shot at the 12th to slip one behind the leaders.

Kim, who finished second in the Corona Championship in Mexico last month, had a faultless five birdie round, while 35-year-old Hetherington, without a win since 2003, had half a dozen birdies, including four in five holes from the seventh.