Fiji beat Papua New Guinea 40-4 in the Bulikula's biggest victory and first World Cup win.
Eight Sharks played for Australia, New Zealand and Fiji in Round 2, and all won.
Australia's 78-0 defeat of England sent the Jillaroos into the semi-finals.
Captain Tiana Penitani Gray set up Chapman's early try, then scored after moving to centre when Julia Robinson broke her wrist.
Quincy Dodd scored on her first tournament appearance, while Ellie Johnston was selected but did not play.
New Zealand beat France 92-0, recording its biggest women's win.
Debutant Chantay Kiria-Ratu scored 22 points alongside Raecene McGregor in the halves.
Annessa Biddle played all 70 minutes and led the match for post-contact metres.
Cassie Staples and Talei Holmes made hard carries; Leilani Ahsam strengthened Fiji's pack, and Nanise Vakacavu started for injured Tamika Jones.
Jaydika Tafua was in Samoa's squad for its 76-0 win over Wales, the Fetu Samoa's biggest-ever victory.
Fiji and Samoa can claim their first-ever semi-final places in Round 3; Australia has qualified.
Samoa meet England on October 30 at WIN Stadium; Fiji face France and New Zealand play Papua New Guinea on October 31 at Cbus Super Stadium.
Australia play Wales on November 1 at CommBank Stadium.
All matches are live and free on Seven and 7plus Sport.