Sam Skinner scored with a minute remaining to go for Exeter to reduce Saints lead to a slender point.
However, Joe Simmonds' conversion attempt never happened as he began his run-up, allowing a fair charge-down with the game ending 13-12 Northamptons.
Fans were not happy, taking to social media to share their 'disgust' with the decision.
SOCIAL REACTION:
All Black legend Dan Carter ranks his five toughest opponents
4&5. Brian O'Driscoll & Paul O'Connell (Ireland)
"Two giants of the game that have worn the green jersey were Paul O'Connell and Brian O'Driscoll. Their work rate and how they conducted themselves on and off the pitch was exemplary."
3. Jonah Lomu (New Zealand)
"He was the toughest player. I played against him once, I was 19-year-old and tried to tackle him, kinda woke up five metres back. He changed the game of rugby.
2. Schalk Burger (South Africa)
“A real competitor and absolute top bloke off the field as well. His mindset was a little bit different when he was out there competing. That just made him such a tough opponent to come up against.”
1. Jonny Wilkinson (England)
"You might of heard of him? Former England captain and Toulon player Jonny is probably the closest thing I've seen to the perfect rugby player."
