Saints duo Ehren Painter and James Grayson started for England Under-20s as they beat Scotland to set up a World Rugby U20 Championship semi-final against South Africa.
Grayson, lining up at full-back, was sin-binned during England's 35-10 victory against the Scots on Thursday evening, with the 19-year-old punished for a high tackle.
Another Saints player, Scotland forward Devante Onojaife, was also yellow carded during the game for the same offence.
And in the end, it was Grayson and prop Painter who helped their team to prevail in Béziers, ensuring England will face the Junior Boks in the final four in Narbonne on Tuesday.
The other semi-final will be between New Zealand and France.
The final will take place in Béziers on June 17.
Saints will hope to have three players involved for England on Tuesday, with centre Fraser Dingwall also part of the Under-20s squad.
Toby Trinder was involved in the opening fixture, against Argentina, but was forced to head home due to injury.