Sydney - The Waratahs ground out an ugly 20-15 win over Western Force to edge into the Vodacom Super Rugby playoff frame in Sydney on Saturday.

The Waratahs scored the only two tries of an uninspiring slog to cancel out James O'Connor's five penalty goals for the Perth-based Force.

Both teams resorted to kicks for territorial gain and relied on their forwards to create a scoring platform with a total of 139 rucks and mauls - 96 of them won by the Waratahs.

The Waratahs lie nine points behind leaders the Reds in the Australian Conference, but importantly they nudged ahead of New Zealand's Highlanders into the top six teams in the overall southern hemisphere provincial championship standings.

The home side had an element of luck with their first try coming off a penalty goal attempt which cannoned off an upright into the grateful arms of former Force centre Ryan Cross.

The Waratahs got their second try when third-choice hooker John Ulugia burrowed beneath a maul to score with 10 minutes left to put his side in front.

Wallaby back Kurtley Beale, who was the most enterprising player on the field, chipped in with two conversions and two penalties.

At one stage in a dour forwards-orientated contest, the Waratahs slogged though 25 phases, hammering away at the Force try-line.

"They made us work for every scrap of possession that we had," Waratahs' skipper Dean Mumm said.

"We didn't get too much clean ball but I'm very proud of the boys for the way they stuck at it.

"To earn those wins is very important in this competition, it's two in a row now and it's important to keep on winning."

It was another narrow defeat for the Force, who have little chance of making the playoffs next month.

"Everyone in these Australian derbies are well paired against each other, the boys have played with and against each other for many years," Force skipper Nathan Sharpe said.

"Full credit to the Waratahs, they ground it out well tonight, but we just didn't take our chances when we had them and we lacked in continuity."

There was concern for Force hooker Nathan Charles who was stretchered off midway through the second half with his neck in a brace after he was knocked out making a tackle.


Teams:

Waratahs:
15 Kurtley Beale, 14 Lachie Turner, 13 Ryan Cross, 12 Tom Carter, 11 Sosene Anesi, 10 Berrick Barnes, 9 Luke Burgess, 8 Ben Mowen, 7 Pat McCutcheon, 6 Dave Dennis, 5 Sitaleki Timani, 3 Dean Mumm (captain), 2 Sekope Kepu, 1 John Ulugia, Benn Robinson

Substitutes: 16 Ben Roberts, 17 Al Baxter, 18 Kane Douglas, 19 Chris Alcock, 20 Brendan McKibbin, 21 Daniel Halangahu, 22 Tom Kingston

Western Force:
15 Pat Dellit, 14 Nick Cummins, 13 Mitch Inman, 12 James O’Connor, 11 David Smith, 10 Willie Ripia, 9 Brett Sheehan, 8 Richard Brown, 7 David Pocock, 6 Matt Hodgson, 5 Nathan Sharpe (captain), 4 Sam Wykes, 3 Matt Dunning, 2 Nathan Charles, 1 Pek Cowan

Substitutes: 16 Ben Whittaker, 17 Tim Fairbrother, 18 Tom Hockings, 19 Ben McCalman, 20 James Stannard, 21 Rory Sidey, 22 Alfie Mafi