Knill said: "John has scored two in the last two games and if I was a centre-half I know I wouldn't want to play against him.
"A lot of the times it looks like it's the centre-half's ball but John gets in there, he uses his body really well and capped a great performance with a great finish off his left foot."
Torquay nearly doubled their lead in a goalmouth scramble just seconds later and from the inswinging corner on-loan Leicester playmaker Jak McCourt bounced the ball off the bar with Bentley beaten.
Knill said: "We all know how important it was to get that win. We have had two weeks to work on shape, we haven't always had that personnel, but this week we have and I thought it showed. I thought we were good value for the win.
"Whenever you are playing a side like Southend, who are on an unbelievable, unbeaten run and full of confidence, you have to be brave and you have to do the things you are good at. I was delighted with the team.
"The two-week break helped the staff as well as the players. It gave us time to breathe and have a rethink.
"Obviously, what we were doing wasn't working so we had to do something else and that's what we have done.
"We have changed the shape and changed the personnel and it's given us a great start to the month. Now we have to repeat that sort of performance again and again."
Southend boss Phil Brown, whose side had won six of their last seven matches in all competitions, said: "I am bitterly disappointed. It was an unrecognisable team performance. To a man you couldn't say anyone played well individually, so collectively you are not going to.
"We didn't play any football. We tended to go route one, maybe because of the conditions. It is all about bottle and pressure and we didn't handle the opposition or the conditions and consequently we got what we deserved - absolutely nothing.
"It was about winning the individual battles and we didn't do any of that and you have to give them credit, they are fighting for their lives and they won the battle.
"It was frustrating for a number of reasons. Performances over October and November have been outstanding but today we didn't play.
"Torquay stepped up to the challenge of keeping their manager in work and well played to them. But for me it is about stepping up to the challenge of what we are about this season. If we can't handle being in play-off situations or automatic spots then now is the time to get out.
"We have played 20 games now and we have got 26 to go. I know what my ambition is and the football club's ambitions - the players have to step up to that ambition and the majority will for the rest of the season."
- Sports & Recreation
- Daniel Bentley