Jamieson and Lynn recovered from two holes down against Italians Francesco Molinari and Matteo Manassero to leave Continental Europe ahead by 5-1/2 to 4-1/2 at St-Nom-La Breteche.
Earlier, Paul Casey and Simon Khan beat Finn Mikko Ilonen and Dane Thorbjorn Olesen 3&2 to give Britain and Ireland the first point of the day.
Belgian Nicolas Colsaerts and Spain's Gonzalo Fernandez-Castano romped to a record-equalling 6&5 win over Paul Lawrie and Stephen Gallacher to restore Europe's two-point advantage.
Jamie Donaldson and Marc Warren saw off experienced European pair Thomas Bjorn and Miguel Angel Jimenez 4&2 before Dutchman Joost Luiten and Frenchman Gregory Bourdy hung on to beat Tommy Fleetwood and Chris Wood by one hole.
Molinari and Manassero looked poised to extend Europe's lead but Jamieson's superb approach shot on the final green set up the birdie which took Britain and Ireland to within one point.
Continental Europe are bidding to win the biennial Seve Trophy, named after the late Seve Ballesteros, for the first time since 2000.