International team captain Mike Weir's selections have faced scrutiny after the Americans hit back hard at the Presidents Cup, grabbing a commanding four-point lead going into the final day's singles matches in Montreal.

Chastened after being swept 5-0 by the Internationals on day two as the hosts levelled the scores at 5-5, the Americans dominated a marathon day 3 made even longer by a 90-minute fog delay at Royal Montreal Golf Club.

They won the morning four-ball matches 3-1 then matched that scoreline in the afternoon foursomes to take an 11-7 lead into Sunday's 12 singles matches, needing to get to 15.5 points to win the Presidents Cup yet again.

Scottie Scheffler and Patrick Cantlay were prominent with crucial efforts as the Americans surged clear late in fading light, while teammate Sam Burns (3-0) is now the only unbeaten player this week.

Adam Scott was the only Australian in action for the Internationals on Saturday, with Jason Day and Min Woo Lee unused along with Christiaan Bezuidenhout and Byeong Hun An as Weir employed the same four pairings in both of the day's sessions.

Lee was sat out for a second straight day after an opening-day four-ball loss. Former world No.1 Day missed out despite winning on day 2 alongside Bezuidenhout.

Playing alongside Canada's Taylor Pendrith, Scott suffered a 2 and 1 loss to Scottie Scheffler and Collin Morikawa in Saturday's four-balls but they bounced back to beat Brian Harman and Max Homa 2 up in foursomes thanks greatly to the Australian.

Scott took his record in event to 2-2 after playing every session.

Impressive South Korean duo Si Woo Kim and Tom Kim got the Internationals' only other win of the day, beating Keegan Bradley and Wyndham Clark 4 and 3 in four-balls.

Weir was keeping faith in four of the five pairings that had earned Friday's 5-0 shutout but his decision not to use others at all raised eyebrows.

"I can't believe that Mike Weir is doing this," said analyst and ex-player Brad Faxon. I just think it's a show of no confidence for the four players who sat."

Weir later confirmed there was no health issue for Day: "We went 5-0 yesterday and had a lot of momentum," he said. "We talked it through and that was it. We had a plan."

Weir asserted Lee could still be a "big weapon" in the singles.

"I was hoping to get him in a little bit more but it just didn't work out that way," he said.

Scott was remaining defiant as he seeks a first Presidents Cup triumph in his 11th appearance.

"We're going to have to be tenacious out there tomorrow and heroic, actually," said Scott.

This is a big format tomorrow, 12 matches, 12 points up for grabs, an incredibly strong US Team. Our guys are going to have to throw caution to the wind and play their asses off."

Day will lead off the singles matches against Xander Schauffele.

Then Tom Kim will face Burns, followed by Hideki Matsuyama v Scheffler, Sungjae Im v Russell Henley, Pendrith v Patrick Cantlay and Si Woo Kim v Bradley.

Corey Conners faces Tony Finau, Lee takes on Clark, then its An v Sahith Theegala, Scott v Morikawa and Bezuidenhout v Harman before Homa tackles Mackenzie Hughes in the anchor match.

The Internationals are trying to beat the Americans for the first time since 1998.

The Americans also led by four points going into the final day two years ago on home soil at Quail Hollow.

The International team have won the singles session only three out of 14 times, all of them when it trailed by at least six points and the cup had been all but decided.

With Reuters