Blues v Chiefs, Eden Park, Auckland

19:35 local, 07:35 GMT, 17:35 EST, 17:05 CST, 15:35 WST

Head to Head: Played 20; Blues 10, Chiefs 10

In Auckland: Played 9; Blues 5, Chiefs 4

Last clash: Round 7, 2013 - Chiefs 23-16 Blues, at Baypark Stadium, Mount Maunganui

Preview: Blues captain Ali Williams leads the Blues out for the last time on Saturday night, having confirmed this week that he's leaving New Zealand rugby at the conclusion of the Super Rugby season, to join what's becoming rugby's new "Galacticos", French club Toulon.

The Blues' already slim finals hopes evaporated with the big loss to the Cheetahs in Bloemfontein last week, and their only motivation now - aside from sending their skipper out a winner - comes with playing the spoiler role against their neighbours from down the highway.

This is crucial game for the Chiefs, though. A loss to the Blues, coupled with a bonus-point win for the Crusaders over the Hurricanes, will see the Chiefs surrender the New Zealand conference lead they've held for most of the season, and, with it, all the home-ground play-offs advantages that come with a top-two finish. The equation is simple: they must win. And I think they will.

Tip: Chiefs by 10

New South Waratahs v Queensland Reds, Stadium Australia, Sydney

19:40 local, 09:40 GMT, 19:40 EST, 19:10 CST, 17:40 WST

Head to Head: Played 20; Waratahs 7, Reds 12, 1 draw

In Sydney: Played 9; Waratahs 4, Reds 5 (* 1-1l at this venue)

Last clash: Round 2, 2013 - Reds 25-17 Waratahs, at Suncorp Stadium, Brisbane

Preview: Remember how I told you in Scrum Five earlier this week that the Reds might actually get a better run through the play-offs if they lost this last match and finished sixth, meaning they're more likely to play the Brumbies in Canberra than have to travel to New Zealand? Should Brumbies fans be reading more into James Horwill and Will Genia's injury withdrawals, or is that just the tinfoil hat talking? Of course, the Reds could still finish fourth, too, with a win and other results going their way.

Anyway, the key Wallabies leaders have been ruled out, with calf and knee injuries respectively, and it will be interesting to see what effect this has on Queensland. The Reds have played without one or the other numerous times over the past years, but not as often without both. Mind you, they did alright against the British & Irish Lions without both of them, and replacement captain James Slipper has the respect of his team-mates. And then there's the whole feel-good buzz around Ewen McKenzie at the moment, too.

The Waratahs will be without their own superstar, with Israel Folau now battling even to be right again for the first Bledisloe Test on August 17. How their other Wallabies back up from the gruelling Lions series is crucial for this game, in which a win could see them finishing seventh overall. A tough one to pick however you slice it up

Tip: Reds by 5.

Western Force v Brumbies, Perth Oval, Perth

19:40 local, 11:40 GMT, 21:40 EST, 21:10 CST, 19:40 WST

Head to Head: Played 10; Force 3, Brumbies 6, 1 draw

In Perth: Played 5; Force 1, Brumbies 3, 1 draw (* Brumbies 2-0 at this venue, 1 draw)

Last clash: Round 11, 2013 - Brumbies 41-7, at Canberra Stadium, Canberra

Preview: Far from a nothing game for either side, but the Force haven't played since June 9 and the Brumbies haven't started since their win over the Lions on June 18. The Force have been trotting around in club rugby, while the Brumbies had nine players involved with the Wallabies. One of them, Pat McCabe, won't play again this season after suffering a recurrence of his 2012 neck injury during the first Lions Test in Brisbane.

The Brumbies may yet finish second with a win over the Force plus a Chiefs loss, giving them the home-ground advantage into the play-offs. They can, in fact, finish first if the Chiefs and Bulls both lose,, but they can't finish any lower than third. A Force win ensures they cannot finish with the dreaded wooden spoon, should other results go against them.

On paper, this is a game the Brumbies should win easily - as you'd expect of a conference-leading team. A loss won't change their table position, but it will be a major disruption heading into the playoffs. The Force will want to finish the season on a high, too, but I expect the class and fitness of the Brumbies to win out after a passionate start from the hosts.

Tip: Brumbies by 14

Sharks v Southern Kings, Kings Park Stadium, Durban

17:05 local, 15:05 GMT, 01:05 EST +1d, 00:35 CST +1d, 23:05 WST

Head to Head: Played 1; Sharks 1, Kings 0

In Durban First match between these teams at this venue

Last clash: Round 4, 2013 - Kings 12-21 Sharks, at Nelson Mandela Bay Stadium, Port Elizabeth

Preview: The Sharks had a shot at upsetting the South African conference-leading Bulls last week only to see fullback Riaan Viljoen push his last-minute penalty goal attempt right of the uprights, having produced moments of truly excellent play alongside moments that have coaches and supporters questioning their life decisions.

That all said, the Sharks - in theory - shouldn't have too many troubles against the Kings, who have found the late-season going tough after a promising start to Super Rugby. Regardless of this result, the Kings face a promotion-relegation showdown with the Lions, who will be looking to re-enter Super Rugby after a year in the wilderness, and with their players disappearing to all corners of the conference. The Kings have rung the changes, too, with only three starters from the Stormers clash retaining their place for the final game of the season. Some changes have been injury-forced, while others have been made with an eye on the Lions.

Tip: Sharks by 15.

Stormers v Bulls, Newlands Stadium, Cape Town

19:10 local, 17:10 GMT, 03:10 EST +1d, 02:40 CST +1d, 01:10 WST +1d

Head to Head: Played 19; Stormers 10, Bulls 8, 1 draw

In Cape Town: Played 9; Stormers 5, Bulls 3, 1 draw

Last clash: Round 2, 2013 - Bulls 25-17 Stormers, at Loftus Versfeld, Pretoria

Preview: The Bulls head to Cape Town to pick up the South African conference trophy that has resided at Newlands for the past two seasons, but also with a chance to claim the No.1 spot on the Super Rugby ladder - and all the home-field advantages that confers through the play-offs. But they know the final match of the regular season against the Stormers will be far from easy.

The Bulls have the luxury of knowing how the Chiefs and Brumbies have fared by the time they kick-off themselves. If either of the other conference leaders drop their final game, the Bulls will be guaranteed a top-two finish. They might then be tempted to rest some weary bodies at the last minute, but that probably won't happen given a top-two finish means the first week of the finals off.

The Stormers will be just as keen to finish on a high, and a fifth successive win to end the season will issue a timely reminder of how good a team they should've been in 2013. Reports out of South Africa suggest Stormers captain Jean de Villiers will return, which might tip the midfield battle towards the home side with young Springboks centre Jan Serfontein ruled out for the Bulls.

This could be the match of the weekend, definitely one to watch (or record, as the case may be).

Tip: Bulls by 3.

Byes: Cheetahs

Make your ESPN FootyTips selections for Super Rugby round 20