The omens were against Bristol before the game even kicked off, with fly-half Jason Strange injuring himself in the warm-up and being replaced in the starting lineup by Danny Gray.
Gray opened the scoring with two penalty goals, before former All Black outside-half Carlos Spencer scored a typically inventive try. Fellow Kiwi Bruce Reihana added the extras and Saints took a 7-6 lead into the break, despite losing another New Zealander, backrower Sam Harding, to the sin-bin for a professional foul.
The third quarter was all Bristol. Scrum-half Jake Rauluni scored in the opening exchanges, with veteran Wales international Gareth Llewellyn rumbling over between Lemi's double.
The Saints hit back with tries to Spencer, Reihana and replacement centre Rhodri Davies, but Lemi had the final say to cement an impressive eight-point victory.
Newcastle Falcons and England star Jonny Wilkinson kicked 16 points in his side's 26-11 victory in front of 4,000 fans at Border Reivers' Netherdale ground.
Young utility back Toby Flood scored the only try of the first half, with Wilkinson adding four goals to give the Falcons a match-winning 16-3 lead at the break
Front-rowers Matt Thompson (Falcons) and Paul Thomson (Borders) exchanged tries in the third quarter, with Wilkinson continuing his comeback from injury with two more goals.
It was one-way traffic at Madejski Stadium, with London Irish giving Italian club Overmach Parma an 80-minute rugby lesson in the 64-0 victory.
The first-half scoring came from a United Nations lineup of Exiles players, with Australian winger Scott Staniforth, Canadian backrower Phil Murphy, Trinidadian-born winger Delon Armitage, Argentinian backrower Juan Leguizamon and Irish backrower Kieron Dawson scoring tries and New Zealand outside-half Riki Flutey adding three conversions.
An Englishman finally dotted down when fullback Michael Horak scored in the 42nd minute, with the promising Armitage getting his second moments later. The Italians regathered and kept the score at 45-0 for 30 minutes, but London Irish finished like a train, with three tries in the final six minutes, including two more to man of the match Staniforth.