USA cut Europe lead after strong end to day two of Ryder Cup
Cantlay and Wyndham Clark won the last two holes to beat Rory McIlroy and Matthew Fitzpatrick 1-up in the gathering gloom as the Americans grabbed the afternoon fourballs session 3-1.
But the visitors will still need the biggest Sunday comeback in Ryder Cup history to lift the trophy on European soil for the first time since 1993.
"It felt big, just trying to get any momentum we can going into tomorrow," said Cantlay who competed without a cap, reportedly in a protest over players not being paid.
McIlroy and Fitzpatrick led 1-up with three holes to play and appeared set to secure a record seven-point advantage after two days for Europe when the Northern Irishman drove the 16th green.
But Cantlay made a crucial birdie, before making it three in succession with his monster effort on the 18th.
The majority of the US team were greenside and celebrated wildly as Cantlay roared in delight, evoking memories of Ian Poulter's famous Saturday heroics before Europe's comeback from 10-6 behind at the 'Miracle at Medinah' in 2012.
That was the last time either side won away from home.
Justin Rose and Robert MacIntyre had earlier fought back to see off Justin Thomas and a struggling Jordan Spieth 3 and 2.
The European pair twice trailed one-down on the front nine but rallied as Spieth misfired badly, Thomas failing to shoulder the burden alone.
MacIntyre had missed a succession of putts over the weekend but made three clutch ones on the back nine.
Rose finished off the job on 16, draining a 19-foot effort for birdie.
Collin Morikawa and Sam Burns gave the USA the shot in the arm they needed in the opening match by racing into a 6-up lead with six to play against Viktor Hovland and Ludvig Aberg.
The Scandinavian duo had thrashed Scottie Scheffler and Brooks Koepka by a foursomes record 9 and 7 in the morning.
But they could not hold off their American opponents who closed out a 4 and 3 success.
Max Homa and Brian Harman won the USA's first full point earlier Saturday and backed it up with a 2 and 1 win over Tommy Fleetwood and Nicolai Hojgaard in the second match.
