Reds had Jake Hesketh sent off but goals from Max Watters and Tim Nichols ensured another win and saw Yems' side rise to seventh.
Yems said: "It could have gone either way. We showed a lot of spirit and a different way to win today. It wasn't all good football. They made it hard, which is why they are top.
"As I said to everybody a few weeks ago, of we haven't got that spirit, they wouldn't be in the team, and that's what we are trying to build.
"On the back of that you have got to earn your right to play football."
On the sending off, Yems said: "Jake gets sent off, I didn't see it myself - I am not giving it the old Alex Ferguson - the linesman give it, not the referee. I am not saying anymore, I can't afford to keep paying fines. He's off but we stick at it and credit to all the players."
And Yems said the spirit in the club is good and the fans should enjoy these victories.
He said: "It's not shape that wins you games, it's players. The spirit we have in the club at the minute is good. On the back of that we have also got some good players, which helps.
"I say to all the Crawley people, enjoy the victories and long may they continue."