Crawley Town goalkeeper Glenn Morris believed his first half penalty save was the turning point in the game.
The club's custodian and goalkeeping coach reckoned Reds improved as the game went on and even matched the league leaders in the second half.
Morris said: "It's a bit of a game-changer the penalty save because if we'd gone 1-0 down it might have been a different result.
"Luckily I saved it, we moved on and grew into the game. I think the second half was fairly even."
Morris had experience first hand of Doncaster's penalty-taker John Marquis as a team-mate at Gillingham during 2015 and predicted he would hit it to the keeper's left, to be different from his regular direction.
He revealed: "I've played with him at Gillingham and I know which side he favoured, it's actually the other side! He scored a few goals (penalties) going the other way.
"I just had a feeling he might go the other way and his run-up was a bit different so I thought stick it the other side, luckily he did. It's a bit of a 50-50, we've got to be happy with that."
Morris, 33, reckoned Crawley got better after the break and managed to earn a good draw which was vital going into another game on Tuesday against another promotion-chasing club, Portsmouth.
He said: ""It was quite a strong wind in the second half and we had a couple of good chances. If we'd had nicked a 1-0 it would have been brilliant.
"On the balance of the play we've got to be happy with a point.
"We needed to get something on the board, we have lost a few at home and it's important going into the game on Tuesday we don't lose again."