Still winless after six games, making finals seems a distant dream for the Capitals even this early in the campaign.

The hosts closed to within five points early in the second half after trailing by 10 at half-time, but a dominant 22-2 run by the Boomers to finish the term snuffed out any hope of a comeback.

Not even the debut of American point guard Renee Montgomery, fresh off the plane after helping Minnesota Lynx to the WNBA title, could turn Canberra's fortunes around.

Montgomery (nine points) showed glimpses of what she can offer once settled in the system with her penetration early, but also committed five turnovers and can't be expected to solve her new side's many problems.

The Capitals at times were guilty of not doing the basics, particularly boxing out on the offensive boards, not helping teammates defensively when isolated and lacking defensive intensity when Melbourne made its third quarter surge.

They conceded 30 points from turnovers to the Boomers' 10, who squared their season ledger at 2-2.

"We ended up losing the possession 47-32 and they had 25 second chance points [to Canberra's eight]," Capitals coach Carrie Graf said.

"We're not going to be in any contest if we don't address that. Our defensive intensity bottomed out, they smashed us on the glass and we got all erratic offensively.

"We didn't block out aggressively all the time and the teams are too good in this league, we can't have lapses like that and we have to hang in games with defence and possession.

"We're a broken record right now. We executed well in the first half and got a lot of shots but we missed a plethora of lay-ups and wide open perimeter shots."

Australian Opals forward Stephanie Talbot has been outstanding for Canberra this year despite its early struggles, but had a match she would prefer to forget.

Talbot, who averaged 20 points a game before the contest, managed only six points and was responsible for eight of Canberra's 20 turnovers.

Third quarters have been a major issue for the Capitals all season and again it cost them dearly, with Madeleine Garrick​ (17 points, eight rebounds), skipper Tess Madgen​ (20 points,  five assists) leading the way.

Reigning WNBL most valuable player Abby Bishop (21 points, eight rebounds) toiled hard for the Capitals against the inside presence of Elyse Penaluna​ (13 points, 14 rebounds, five assists), who continued her strong start to the season with a double-double.

MELBOURNE BOOMERS 91 (Tess Madgen 20, Madeleine Garrick 17, Elyse Penaluna 13)

CANBERRA CAPITALS 63 (Abby Bishop 21, Renee Montgomery 9)

at AIS Arena on Saturday night. Crowd: 525