Paris - French Top 14 leaders Lyon came crashing down to earth at Franklin's Gardens on Sunday as they slipped to a 25-14 defeat in their opening European Champions Cup Pool 1 match against Northampton.
French spirits took a double dip as Montpellier were squeezed 23-20 by Connacht in their Pool 5 encounter in Galway.
Northampton, winners in 2000, opened up a 19-0 lead at half-time thanks to a converted Rory Hutchinson try and four penalties from Dan Biggar.
But in a fractious second half which saw the game interrupted on several occasions by outbreaks of fighting, Lyon began to show their worth with replacement centre Thibaut Regard crashing over twice.
Lyon were denied a defensive bonus point, however, by two further penalties from Biggar who finished with a personal haul of 20 points.
Montpellier took the early initiative against Connacht with former All Black Aaron Cruden going over for a try in the first minute.
The home side hit back with a penalty from Jack Carty and two tries just before half-time from flank Paul Boyle and hooker Tom McCartney.
Trailing 13-10 at the break, Montpellier levelled through a Benoit Paillaugue penalty but Connacht soon pounced for their third try as scrumhalf Caolin Blade darted through a gap close to the French line.
With 15 minutes remaining, Montpellier drew level again at 20-20, Anthony Bouthier getting the better of McCartney to sprint through, Paillaugue adding the extras.
Four minutes later replacement flyhalf Conor Fitzgerald converted another penalty and Connacht clung on for the win.
The result means all four Irish provinces won on the opening weekend of the Champions Cup.
European Champions Cup results on Sunday:
Northampton (ENG) 25 Lyon (FRA) 14
Connacht (IRL) 23 Montpellier (FRA) 20
Racing 92 (FRA) 30 Saracens (ENG) 10
Played on Saturday:
Leinster (IRL) 33 Benetton (ITA) 19
Glasgow Warriors (SCO) 13 Sale (ENG) 7
La Rochelle (FRA) 12 Exeter Chiefs (ENG) 31
Bath (ENG) 16 Ulster (IRL) 17
Clermont (FRA) 53 Harlequins (ENG) 21
Ospreys (WAL) 13 Munster (IRL) 32
Played on Friday:
Gloucester (ENG) 20 Toulouse (FRA) 25