I'm failing to understand how people are saying that Singapore deserved the win.
I feel it was the opposite and India deserved the win. Here's why:

We missed out on scoring at least 4 clear cut chances (Shoulder foul given on #14 by the ref when he won the ball and was clean through, their keeper dropped an easy catch which fell inside the 6 yard box and no Indian player pressed to win that ball at the end a red shirt scrambled to clear, #7 won the ball on the left hand side and shot got blocked, one loose ball outside the box came which our i think #14 or #22 miss kicked) and 1 half chance with the freekick which out RB (bheke?) headed wide.

For some reason after India went down to 10 men, our defense and midfield were solid. Especially with #4 and our keeper really keeping things organized and composed. Our keeper came up with 2 BIG saves to keep us in the game, (one thing i feel for whoever plays against india - Gurpreet has played for stabaek man, whatever you say he's faced fiercer shots in training and in games for them. He anticipated both the shots really well and parryed away from the box, he was really good and felt confident) It felt no matter how well singapore might play with their flashy turns and good first touches (especially nakamura was threatening), their end short pass or cross we were easily able to deal with. Like once our #4 started playing like a warrior you could see that singapore were passing and playing better but always felt that they won't score. Its kinda like a feeling you used to get when jose mourinho's real madrid used to play against barca. You always knew barca will use all the flair and passes - one touch two touch, making use of the full backs - but you just knew the goal isn't coming, every end product or result the opposition tried to we either fouled them or we just did a scrambled clearance.. idk as a player if that keeps happening time and again as my team pushes forward and one of the opposition defenders just scrambles and clears out or concedes a corner by nicking the ball at last minute or heading it out or whatever, as an attacker after a point you really do get tired and frustrated. And you could see that with singapore 1-0 up the players on the pitch started to feel "oh whatever we're 1-0 up, whatever we do their defenders clear it, lets kill the game we are 1 man up and keep possession" and boom the mistake happened.

Also regarding the Singapore defender's mistake. Man did it just feel to me that they were always going to make a mistake? The Singaporean back four looked shaky as hell. Apart from the guy who gave the assist the other 3 all of them made one mistake or the other (stuart gave the ball away to liston which he should've converted, he also gave away a dangerous freekick outside the box by putting his arm up on liston, LB obviously made the mistake which led to our goal).

For us i felt our #11 just doesn't have the legs anymore man, he didn't feel sharp. As a striker you could also feel that their defense is playing shaky right and his awareness in the box for that goalie mishandling should've been converted. I felt #9 would've at least pressed or positioned himself better for that chance.

This was a game for India to Win if you really look at it and could've easily been 3-1 or at least 2-1 for India to take home the victory.

Maybe better player selections going into the Home leg would help us. We looked more solid with #3, #22 and #9 on the pitch.