One of just two teams to break par in singles on Friday, Granada and Troche managed only a 3-over 75 in the foursomes format Saturday.
They are at 2-under par 214 -- still four shots ahead of Italy, the same margin they held over Japan following Day 1.
'It was a very tough day. Pars were a good score out there,' said Troche. 'We were burning the edges of the hole with birdie putts for most of the day and I think we just wanted it too much.'
Troche made a 30-foot putt at No. 18 for their second birdie.
'I think we managed to keep it together really well and that birdie at the last will give us a lot of momentum going into the last day,' said Granada.
Italians Giulia Sergas and Veronica Zorzi combined for a 1-over 73 and moved into second place at 2-over 218.
Americans Pat Hurst and Juli Inkster were the biggest movers Saturday, sliding into third place at 3-over 219 after posting a 2-under 70 -- the only round under par in foursomes.
Hurst and Inkster had opened poorly with a 5-over 149 in singles and were 10 shots behind Paraguay at the beginning of the second round.
'We ham-and-egged it pretty well all day,' Inkster said. 'We weren't in much trouble at all and played smart golf.'
South Korea -- second place overnight -- slipped to fourth place following a 5-over 77. Ji Yai Shin and Young Kim are at 4-over 220.
Scotland (221) is fifth, while Australia and Finland (222) share sixth place.
The first two World Cup champions, Japan and Sweden respectively, remained non factors: Japan is 15th following a 78, and Sweden is tied for 19th after an 81.
The 22-team field will finish the tournament Sunday with a better ball format.