Four second-half tries gave the NSW Waratahs a chance to produce a miracle win, but it wasn't enough as the Chiefs ran away 46-31 winners in Hamilton on Saturday.

With the Brumbies cruising to a 32-3 win against the Rebels in Canberra, the Tahs' horror season is officially over. The side from the ACT will be the only Australian team in this year's finals series, as they topped the group and secured a quarter-final berth with the win.

Staring down the barrel of their heaviest defeat this year, Rob Horne's 50th minute intercept try and Will Skelton's clever work from a rolling maul put the Waratahs down 32-17 with 23 minutes remaining and with a faint hope of victory.

That hope grew even more when Cam Clark (73rd) and Sekope Kepu (74th) both scored tries of their own to get the score to 39-31, but all chances were extinguished when James Lowe crossed for his hat-trick in the 79th minute.

"The damage was done in the early stages of the second half," coach Daryl Gibson said. "The Chiefs got on an excellent roll and then for us the yellow cards were pretty costly.

"While against New Zealand teams we remain very competitive, we're still not good enough to win.

"Already being down 15 points at half-time made it difficult. I've always known we've had excellent fight and we'll always come back and keep ourselves in the contest, but our missed tackle ratio was high ... so it's hard to be competitive if you miss that many tackles."

The numbers for Australian rugby teams are becoming even more depressing, with the Waratahs' latest defeat marking loss No.22 this year for Aussie sides against their New Zealand rivals.

As for the Waratahs themselves, they have now been beaten in nine of their 13 matches in what will go down as one of their worst seasons in history.

The Waratahs went into the last match before the June Test window knowing nothing but a win would suffice.

Now they will return to Sydney with their season over, with games against the Jaguares in Sydney and Western Force in Perth remaining in July.

Gibson has sounded like a broken record in recent weeks, asking for an 80-minute performance from his side, something they have been striving for all season.

On the evidence we have seen this year, it might be a while before NSW achieve this - at least for as long as they give away easy ball through turnovers and schoolboy errors.

NSW have been the second worst team in the competition for turnovers conceded, and that was no more evident than in the early passages of play when Tom Robertson and Clark gave the ball away thanks to hungry Chiefs players over the ball.

It is an area that has crippled the Waratahs at stages this year.

The Chiefs edged ahead with a penalty goal before Bernard Foley missed a relatively easy attempt shortly after.

The frustration would have bubbled over in the 15th minute when Mitchell Brown crossed for the first five-pointer of the match.

In the lead-up, three Waratahs players missed tackles on Anton Lienert-Brown, who passed to another Chiefs player, who then offloaded to Brown in what was all too easy for the hosts as they went 10-0 up.

The Waratahs struggled for possession and territory in the opening half, making their goal of establishing quality front-foot ball all the more harder thanks to the brilliant work of Chiefs five-eighth Damian McKenzie, who set up Lowe for the second try of the game.

McKenzie's ability to create something from nothing is admirable and the lightning speed at which he passes the ball put him in a different league to incumbent Wallabies No.10 Bernard Foley on Saturday.

All year captain Michael Hooper has begged his Waratahs to show better discipline across the 80 minutes.

Last week it was Dean Mumm, and on Saturday it was Tolu Latu who had a brain fade in the 38th minute, tripping McKenzie who was trying to regather a short chip over the top.

A yellow card was warranted, but it has been the story of the Waratahs' year, with Latu – and then Paddy Ryan late in the match for aggravating a situation – becoming the ninth and 10th NSW players to be sent to the bin.

The silver lining? Watching prop Kepu trying to throw lineouts, albeit with a degree of success.

The half-time score of 18-3 flattered the Waratahs, for the Chiefs could have piled on 30 points by that stage.

That was evidenced in the three minutes back after the break when Lowe crossed for his second try thanks to a perfectly timed out-the-back pass from halfback Tawera Kerr-Barlow.

Then it was Kerr-Barlow who got in on the action, scoring one of his own before a McKenzie conversion put the Chiefs ahead 32-2.

Kepu's try will go down in rugby folklore, with the big prop running 60 metres and fending off McKenzie to plant the ball down in the corner in one of the great displays of strength and determination.