A desperate Crusaders team stole the Chiefs' thunder and a chance for the home side to sew up a Super Rugby home semifinal with a standout set-piece forward effort at Waikato Stadium tonight.

The Crusaders grabbed a 28-21 victory, hanging on by their fingertips and some outstanding defence at the end as the Chiefs hammered their line well after the final hooter.

The result keeps the Crusaders' hopes alive of reaching the top-six playoffs, while the one bonus point by the Chiefs takes them within one point of a home semifinal.

The Chiefs now need other results to go their way and maximum points from their final match, away to the Hurricanes in Wellington next Friday to take top seeding into the playoffs with the Stormers now poised to move ahead of them if they beat the Cheetahs in Bloemfontein.

The Chiefs started the match without their captain Craig Clarke, the big lock ruled out with a bout of flu and replaced by Romana Graham, with Mike Fitzgerald moving onto the bench.

Whether or not that had any bearing on proceedings we will never know but the Chiefs spent the first quarter of the match responding badly to the big occasion and making error after error under pressure.

And the lineout proved a major Achilles heel for the home side as they mucked up at least eight of their own throw-ins.

After a brilliant Chiefs opening that featured Aaron Cruden fielding a Robbie Robinson bomb and making a break before Tawera Kerr-Barlow carried it on to just short of the line, the home side came away only with three points from one of Cruden's three first-half penalty goals.

From then on the Crusaders seemed to take control, winning their own kickoffs from the well-patented Dan Carter-Kieran Read short, flat restart and the Chiefs looking extremely shaky at set-piece time.

Carter levelled the scores and then converted a right-corner try to Read for a 1-3 advantage after a Robbie Fruean intercept had initially put the visitors back on attack.

Carter's wipers kick to Zac Guildford in the left corner had the Chiefs defending desperately and eventually fullback Israel Dagg delivered the perfect short pass to Read charging back on an angle to score in the other corner despite a juggle as he went over the line.

Cruden reduced the deficit temporarily with another penalty goal but Carter followed a couple of minutes later with a dropped goal to restore the seven-point lead and the mistakes kept coming from the men in red, yellow and black.

A missed touch finder from a penalty by Cruden and then a knock-on followed by penalty concession by hooker Mahonri Schwalger had the Chiefs under pressure and when Liam Messam was caught offside defending a Crusaders lineout drive, Andy Ellis darted down the blindside under advantage and grubbered infield for lock Luke Romano to score.

Carter nailed the conversion and with 20 minutes gone the visitors had a telling 20-6 lead.

But the home side steadied themselves, held onto the ball better and got some attacks going wide, forcing attacking scrums and penalty advantages before lock Brodie Retallick was put into a hole by a clever delayed short pass by outstanding halfback Kerr-Barlow and dived over to score.

Cruden converted and after a spectacular counter-attacking break by loosehead prop Sona Taumalolo kept the pressure on, Cruden added a penalty goal from close range to narrow the margin to 20-16 by halftime.

The Chiefs' scrum got some revenge straight after the break, forcing a penalty near halfway and Cruden hit the upright from 47 metres.

But it was not such good news in the lineout department when the home team lost their first two throws to again put themselves under pressure.

In the end the Chiefs were unlucky to concede a try to Ellis when TMO Bryce Lawrence gave referee Steve Walsh the go-ahead to award it after replays showed Kerr-Barlow had clearly tackled him short and only the added momentum of the late arriving Sam Whitelock got him over the line.

Carter's kick hit an upright, the third poster of the night, and the Chiefs' reply was immediate.

Kerr-Barlow again probed the Crusaders' defences, this time in the right corner, somehow slipped a pass to Sonny Bill Williams and the big second-five who had been largely anonymous till then somehow kept his ball carrying arm free in a four-man tackle and lunged over for the try.

At 25-21, with Cruden missing the conversion, it was anyone's game. But again it was the Crusaders' set-piece that grabbed a stranglehold on the game going into the final 10 minutes and the Chiefs were forced to play the game in their own territory.

When they finally emerged to attack for the last five minutes, including well after the final hooter, it was the Crusaders' defence that held.

One overlap was ignored when replacement hooker Hika Elliot went on his own and then some blatant offside at the end by an otherwise outstanding Richie McCaw after a string of penalties and taps was ignored this time by Walsh and he blew for fulltime when play came to a halt.

Scorers: Crusaders 28 (Kieran Read, Luke Romano, Andy Ellis tries; Dan Carter conversion, 2 penalty goals, dropped goal) Chiefs 21 (Brodie Retallick, Sonny Bill Williams tries; Aaron Cruden conversion, 3 penalty goals). Halftime 20-16 Crusaders.

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