Eder Militao's second-half opener for Real was canceled out by Angel Correa in injury-time. Before then, the match was suspended as fans targeted Real goalkeeper Thibaut Courtois. Atletico's Manuel Llorente was also sent off in the final minutes.
Ancelotti said: "I always think positively. Not negative. Given what happened here last year, it could be a good point for the future. We've also cut a point from the league leaders and we're in a good run of form with all the games we're playing. We're now focusing on Wednesday's game".
"This draw is quite different because we were so close to winning it, but what happened can happen because the opponents are strong, they have resources and a lot of quality. It's a pity that it came in the last few minutes. We did very well when we took the lead, controlling the game. We came very close. We kept fighting. We're not despairing about that. A draw here is a possibility.
"Both sides controlled the game. It could happen and the objective for us was to defend better than last year and we did that. We could have had more speed on the ball, but you have to remember that we play a lot and the tempo can't always be at full throttle in every game".
On Atlético's equaliser, he said: "When you're ahead with five minutes to go there's only one thing you need to do: defend. We did that and we did it very well for most of the game, but it was a very good move, a perfect through ball and they scored a goal"
On the suspension of the match, Ancelotti added: "It was the right thing for the referee to do. We had to stop the game for 10 minutes. We changed a few things in the dressing room and we started again. Nobody liked this stoppage, but the referee was right.
"I don't think the team switched off because of the stoppage. It affected both teams the same. They threw the lighter and the game was stopped twice. The referee told us to rest for ten minutes and after that, we'll start again."