Bristol coach Richard Hill:
"Many of this side haven't played here before in front of a big crowd and we just did some silly things.
"It was a lack of composure under pressure that was uncharacteristic.
"The first 40 minutes were riddled with errors and this was disappointing. And when we got the bonus point we nearly threw that away."
Northampton: Reihana; Rudd, Clarke, Vilk, Diggin; Spencer, Howard; Smith, Thompson, Budgen; D Browne, Lord; Seely, Lewitt, D Browne.
Replacements: Robinson for Howard (41), Hartley for Smith (73), Noon for Budgen (77), Gerard for Seely (77), Harding for Lewitt (73), Tupai for D. Browne (58). Not Used: Patston.
Bristol: Stortoni; Robinson, Lima, Cox, Lemi; Strange, Perry; Hilton, Regan, Crompton; Winters, Llewellyn; Salter, El Abd, Ward-Smith.
Replacements: Irish for Hilton (66), Lewis for Salter (67). Not Used: Nelson, Sambucetti, Rauluni, Hayes, Higgitt.
Sin Bin: Ward-Smith (74).
Att: 13,485
Ref: Martin Fox (RFU).