Update: 10:15PM Playing a quarter of the match with 14 men, the Sharks ground out a 29-23 Super Rugby win over the Blues in Auckland on Friday.
The competition leaders played most of last week's 30-25 win over the Crusaders a player down, and two yellow cards meant they had to survive 20 minutes of the round 15 match at Eden Park a man down.
But the Sharks' vaunted defence held strong, and they return home with two rare wins from their New Zealand tour, consolidating their lead on the Super Rugby table.
It took less than 10 minutes for hooker Bismarck du Plessis to barrel across and open out a 10-3 lead for the visitors, instant punishment for the Blues after they coughed up possession inside their own 22.
Another Simon Hickey penalty narrowed the gap, but the Sharks were looking ominous, attacking the breakdown, forcing turnovers and capitalising on Blues errors.
Francois Steyn sunk a dropped goal to re-establish a seven-point margin after 27 minutes, but the Blues were starting to make some impact with a series of good driving mauls.
They backed themselves in kicking for the corner at the half-hour mark, bypassing a surefire three points from a penalty to attack the Sharks' line from the lineout.
But the South African defence, which has conceded just 16 tries all season, was repelled the challenge and took a 16-6 lead into halftime.
The Sharks were again left short after the restart, prop Jannie du Plessis sinbinned for offside play in the first minute.
The Blues made the most of it, skipper Luke Braid barging across from the resulting scrum for the try.
But Steyn continued to kick the penalties, and the Sharks continued to capitalise on the Blues errors, halfback Cobus Reinach toeing ahead and winning the race for the line to give the South Africans a 26-13 lead after 55 minutes.
Tevita Li narrowed the gap when he finished off some smart Blues handling with a well-taken try out wide with 13 minutes remaining but the Sharks showed iron discipline and superb defence to close out the win.