Jeremy Henry kept alive his bid for a fourth straight World Cup title and teenager Jamie-Lee Worsnop ensured Australia had a representative in the women's semi-finals after both won elimination play-off matches at Warilla Bowling Club.

Worsnop, 18, is the youngest Australian representative in the World Cup and showed her poise with a tense tie-break win over South African Colleen Piketh in Tuesday's play-off.

Worsnop finished third in section two (5-2 win/loss record) behind Malaysian star Siti Zalina Ahmas (7-0) and beat section one runner-up Colleen Piketh 6-8 7-4 3-2 to earn another clash against Ahmas in Wednesday's second semi-final.

Meanwhile, Henry is playing well following a 9-6 9-5 win over Spanish rep Pete Bonsor, the former Towradgi Park BC member.

Henry finished second in his section behind Scotland's Iain McLean and his win over Bonsor set up a clash against Australia's other men's representative David Holt in Wednesday's semi-final.

"Every game is a knockout here on and you can't have a bad game," Henry said.

"It's been a long tournament and three of us finished equal in our pool, which shows how close it is."

The winner of both sections of the men's and women's indoor singles tournament advanced directly to the semi-finals, while the second and third-placed bowlers in each section played off in Tuesday's quarter-final.

McLean, Henry and Guernsey's Todd Priaulx all finished with an 8-1 win/loss record in their section with McLean claiming top spot on countback, after winning the most sets (14), one more than Henry, with Priaulx third with 11 wins.

Having beaten Bonsor, five-time world champion Henry now takes on Holt in a Northern Ireland versus England match-up, though both adopted Aussies are representing Australia at the World Cup.

Holt won a gold medal at the 2002 Manchester Commonwealth Games for England and in his first World Cup appearance claimed his section with an impressive eight wins from nine matches.

On the other half of the draw, Priaulx on Tuesday eliminated New Zealand's Ali Forsyth in a third set tie-break 11-6 2-11 2-1 and now faces his section two rival McLean in the second semi-final on Thursday morning.

Finally, four-time champion Jo Edwards (New Zealand) will meet Scotland's Julie Forrest in the first women's semi-final on Wednesday morning.

Edwards will be a strong favourite after not losing a set in a clean-sweep of eight sectional wins. Edwards has won 15 sets, plus drew one set against South African Colleen Piketh.

Forrest booked her semi-final spot with an 8-5 12-3 win over Canada's Kelly McKerihelly in their play-off match on Tuesday.

The semi-final schedule on Wednesday is Edwards v Forrest, followed by Henry v Holt and Ahmas v Worsnop.

On Thursday, McLean takes on Priaulx, followed by the women's and men's final.