Nicolas Colsaerts birdied Nos. 15 and 17 to protect his slim lead and edge Paul Casey by a hole. Joost Luiten had won four matches in the competition, but lost 3 and 2 to Tommy Fleetwood, who went three up on the front nine.
Gregory Bourdy of France became the first player to win five points in a single Seve Trophy, making six birdies to rout Scott Jamieson 4 and 3.
After Marc Warren thrashed Thorbjorn Olesen 4 and 3, Matteo Manassero defeated Stephen Gallacher 3 and 2 to give Continental Europa a 13-12 lead before Miguel Angel Jimenez pushed Britain and Ireland to the brink by dominating David Lynn 6 and 4.
Paul Lawrie beat Mikko Ilonen 2 and 1 to keep alive his team's hopes of a tie that would have forced a greensomes sudden death playoff.
"They were very strong. We gave it everything, but came out just short," Britain and Ireland captain Sam Torrance said.
Molinari went three up after 10 holes and birdied No. 16 from 12 feet to decide his match against Wood.
"It was funny yesterday when Olazabal was reading the list," Molinari said. "I kind of knew I was going to be last, but I was waiting every name, hoping to hear mine, and I didn't until the 10th spot.
"You've got nine teammates here and the captain, and you don't want to let anyone down. I've done it twice now going last in the singles, I don't know if I want to do it again."
