Elfyn Evans holds a shock Rally Argentina lead in the DMACK Ford after setting the pace throughout a chaotic opening morning.
Only four factory World Rally Championship drivers had a completely trouble-free start, but even before the attrition set in Evans had already taken charge of the rally.
DMACK has brought a new tyre to this event, a harder version of its soft compound and featuring a lighter side wall, and Evans made good use of it to win all three full-length stages so far.
Initially Kris Meeke and Dani Sordo were able to keep Evans in sight, but both hit trouble.
Sordo had to stop and change a broken steering arm on his Hyundai after striking a rock on the Amboy stage, costing him 11 minutes.
Meeke flew off the road when caught out by a bump on the following Santa Rosa stage, doing substantial damage to his Citroen.
He got going again and reached the stage finish having lost just over six minutes, but faces a challenge to get his mangled car through the upcoming superspecial and back to service.
All that put Jari-Matti Latvala up to second, despite losing some front aero on his Toyota on the first stage.
Latvala was part of a very tight five-car battle for most of the morning but drew nearly nine seconds clear of it by going second-quickest to Evans on Santa Rosa. The Finn trails the Welshman by 23.6s overall.
WRC leader Sebastien Ogier was as low as seventh, having done slight aerodynamic damage to his M-Sport Ford when an incorrect pace note led to him exploring a ditch on the opening San Agustin stage.
He regained a little ground on SS3 then felt running first on the road was particularly costly on SS4, leaving him fifth.
The champion is at the tail of a very close all-Ford fight for third, with 3.5s covering WRC returnee Mads Ostberg and works M-Sport duo Ott Tanak and Ogier.
Set-up changes after a poor first stage helped Tanak surge forward with third-fastest times on the next two stages.
Thierry Neuville was in the thick of this battle at first before a broken damper caused him to drift away from it. His Hyundai is 12.3s off Ogier in sixth.
Last year's Argentina winner Hayden Paddon rolled on the day's very first stage, but the level of attrition - and the fact he sustained minimal damage and got going within two and a half minutes - means he is already back up to ninth behind Lorenzo Bertelli and WRC2 leader Pontus Tidemand.
Juho Hanninen has been drastically slowed by a loss of power on his Toyota, which started after a rough ride over one of many vicious compressions on the early stages. He runs a distant 10th.
Craig Breen is formally classified 14th in his Citroen C3, but has retired from Friday's competition with a broken gearbox.
Breen had run a largely anonymous eighth after the morning's first two stages, away from the squabble for the podium places, but lost five minutes on SS4 while stuck in fifth gear.
Although the Irishman was able to complete the stage, Citroen later confirmed that Breen's car had been retired for the day as a result of the issue.
LEADING POSITIONS AFTER SS4: