A masterclass in awful weather from England prospect Fin Smith helped Northampton Saints claim a famous 26-23 triumph against Munster in the Investec Champions Cup.

Despite having hooker Curtis Langdon red carded just before half-time, Northampton dug in and produced an impressive performance in the second period to seal victory.

Smith kicked a drop goal, three penalties and converted both Alex Mitchell and Sam Graham’s tries as the celebrated a memorable win that seals top spot in Pool 3.

Peter O’Mahony, Antoine Frisch and Gavin Coombes claimed ‘s touchdowns, with fly-half Jack Crowley kicking a conversion and two penalties on a windy night.

Langdon was dismissed just before half-time following reckless contact with his knee to Munster second-row Tom Ahern’s head at a ruck.

Saints skipper George Furbank had already been sin-binned for a dangerous tackle, and Munster flanker O’Mahony pounced for a try when Saints were briefly reduced to 13 players.

But uncapped Six Nations squad fly-half Smith ran the show in a 16-point haul that will no doubt have caught the attention of head coach Steve Borthwick.

Smith displayed outstanding tactical control in driving rain as Northampton posted a statement victory, with Munster also progressing among four qualifiers from the

.

Saints had already qualified for the Round of 16 following victories over Glasgow Warriors, Toulon and Bayonne, and they fought back from a 10-point deficit early in the second period to prevail.

Their boss Phil Dowson sent his strongest available side to Thomond Park and wild celebrations at full-time justified his decision in a result that will only add to their confidence.

The teams

Munster: 15 Simon Zebo, 14 Calvin Nash, 13 Antoine Frisch, 12 Alex Nankivell, 11 Shane Daly, 10 Jack Crowley, 9 Craig Casey, 8 Gavin Coombes, 7 John Hodnett, 6 Peter O’Mahony, 5 Tadhg Beirne (c), 4 Tom Ahern, 3 Oli Jager, 2 Niall Scannell, 1 Jeremy Loughman

Replacements: 16 Eoghan Clarke, 17 Josh Wycherley, 18 John Ryan, 19 Brian Gleeson, 20 Alex Kendellen, 21 Paddy Patterson, 22 Joey Carbery, 23 Seán O’Brien

Northampton Saints: 15 George Furbank (c), 14 Tommy Freeman, 13 Fraser Dingwall, 12 Rory Hutchinson, 11 Ollie Sleightholme, 10 Fin Smith, 9 Alex Mitchell, 8 Juarno Augustus, 7 Tom Pearson, 6 Courtney Lawes, 5 Alex Coles, 4 Temo Mayanavanua, 3 Trevor Davison, 2 Curtis Langdon, 1 Alex Waller
Replacements: 16 Robbie Smith, 17 Emmanuel Iyogun, 18 Elliot Millar Mills, 19 Alex Moon, 20 Sam Graham, 21 Tom James, 22 Burger Odendaal, 23 Charlie Savala

Referee: Tual Trainini (Fra)
Assistant Referees: Ludovic Cayre (Fra), Flavien Hourquet (Fra)
TMO: Eric Gauzins (Fra)