A brilliant 90 from opener Naomi McDonald underpinned Sydney's big win over Penrith as the McDonald's Women's Premier Cricket reignited on Sunday.

After two weekends of washouts, all eight teams were thankful to get underway in favourable conditions - and McDonald quickly made up for lost time.

She needed only 61 minutes and 55 balls to reach 90, smashing 16 fours along the way at batter- friendly Howell Oval.

McDonald and Olivia Maxwell (57 not out) put on 107 for the second wicket, allowing Sydney to set-up an imposing target of 4-172 from 20 overs.

Despite a fighting run-a-ball 44 from Elsa Hunter, Penrith was never really in the hunt.

The hosts finished their 20 overs on 4-105 as Sydney swept back to the top of the ladder.

"Naomi’s innings was brutal and clinical all in one," Sydney's head coach Russel Grimson said.

"She had a clear plan which she executed well, punishing anything loose and turning the good balls into scoring opportunities.

"She showed again why she wouldn’t be out of place in any WBBL side.

"Olivia was also outstanding in scoring her maiden half-century in first grade.

"Both players have a great temperament and desire to succeed, which rubs off on their teammates."

St George-Sutherland maintained its undefeated start to the season after seeing off early competition leaders Parramatta.

Thanks largely to Naomi Woods (3-7) and Jaclyn Vickery (2-16), the Slayers contained Parramatta to just 61 from their 20 overs.

Openers Joanne Kelly (24) and Rhiannon Dick (24 not out) chalked off 57 of the 62 required to ensure an easy nine-wicket win.

In the other games, Northern District lost just two wickets in defeating Bankstown and Gordon disposed of Campbelltown-Camden.

Sydney, NDs, St George-Sutherland and Parramatta make up the top four after four rounds.

Scores here