Westford’s Molly Smith earned medalist honors at the 120th Massachusetts Women’s Amateur Championship.

The 18-year-old, a recent graduate of Westford Academy, fired a sizzling 2-under par 68 to finish the two days of stroke play with a 143 (3-over), which was five shots better than Mekhala Costello of Blue Hill CC (73-75-148) at Dedham Country & Polo Club.

Smith, 18, is trying to duplicate the formula used by her oldest sister, Morgan, 19, who also won stroke play by five shots last summer en route to winning the championship.

The Smiths were well represented atop the leaderboard heading into Wednesday and the first day of match play. Maddie Smith, 15, was in third (+9) after rounds of 76-73-149. Morgan Smith (78-73-151) was tied for fourth with Shannon Johnson of Thorny Lea, Isabel Brozena of Indian Ridge and Allison Paik of The Cape Club of Sharon.

All three Smiths are representing Vesper CC of Tyngsboro.

This year’s champion will be crowned Friday.