CAPE TOWN, South Africa (AP) — The Lions and Crusaders will host the Super Rugby semifinals, and the Hurricanes and Chiefs will attempt to upset the tournament's top two seeds.

Super Rugby's last four was decided on Saturday as the Crusaders blanked the Highlanders 17-0 in terrible weather, the Lions escaped with a 23-21 win over the Sharks, and the Chiefs beat the Stormers 17-11 in a grind in Cape Town, South Africa.

Those three joined defending champions the Hurricanes, who prevailed over the ACT Brumbies on Friday.

The Chiefs have to travel back to New Zealand to try to stop the Crusaders in Christchurch. The Crusaders have lost just once in 16 games this season.

The Hurricanes will face the testing trip to altitude in Johannesburg to play the Lions, who also have just one loss.

The Crusaders moved closer to a record-extending eighth title when they saw off the Highlanders in conditions which were among the worst in the tournament's history.

The Highlanders were delayed in reaching Christchurch by a severe storm which grounded planes and cut the main road between the two South Island cities. They arrived on Saturday afternoon, hours before kickoff and after Christchurch declared a state of emergency because of widespread flooding.

The field at AMI Stadium was awash, and rain continued throughout the match. The Crusaders, helped by a test-strength tight five, adapted better to those conditions, scored two first-half tries and held on through a scoreless second half.

Poor discipline, which led to an 8-2 penalty count in the Crusaders' favor in the first half, made life more difficult for the Highlanders who lost back-rower Liam Squire to the sin-bin in the fourth minute for a dangerous tackle. The Crusaders scored their first points when Richie Mo'unga kicked a goal from the resulting penalty.

The first try came in the 33rd when, after holding the ball through 15 phases, the Crusaders pressed the Highlanders' line. Back-rower Kieran Read carried the ball to the tryline and prop Joe Moody drove it over.

Referee Angus Gardner awarded the Crusaders a second try three minutes later, to flanker Jordan Taufua after a powerful lineout drive, but was forced to reverse his decision when the television match official said the ball was not grounded.

The Crusaders made up for that minor setback almost immediately, winning a five-meter scrum, carrying the ball to the line and scoring when hooker Codie Taylor dived through the pile of forwards to the line.

In Johannesburg, the Lions nearly wasted their No. 1 seeding for the playoffs, and needed a 77th-minute penalty from their own half from wing Ruan Combrinck to edge past the Sharks and avoid a big upset.

The Lions topped the regular-season standings, but produced nothing near their regular-season form in an error-strewn first half at Ellis Park, where they dropped passes and missed kicks at goal to trail 14-3 at the break.

The Sharks, written off before the game after squeezing into the playoffs as the lowest seed, scored a first-half try by Kobus van Wyk off a turnover, when the Lions tries to run from their own 22. The Sharks pounced on nearly every Lions mistake in that first 40.

The home team rediscovered the attacking accuracy that took it to the top of the league standings with tries by Franco Mostert, Jaco Kriel and Lionel Mapoe in the first 20 minutes of the second half. That put the Lions ahead 20-14.

There was still drama to play out, though, with Sharks loose forward Daniel du Preez powering over with 15 to go and forcing the Lions to scramble again.

Combrinck was left with a shot from inside his own half right at the end to steal the win, after already missing a much easier kick. He landed the late, 55-meter shot and the Lions clung on.

The Chiefs and Stormers played out an arm wrestle at Newlands.

Chiefs fullback Damian McKenzie's boot was the difference until right at the end, when the visiting Chiefs — leading by just a point at 12-11 — sealed a place in the semis with a try in the right corner to replacement Shaun Stevenson with four minutes to go.

"It took a massive effort," Chiefs flyhalf Aaron Cruden said. "We'd rather win ugly than lose pretty."