The only risk free is not to gamble at all. As per average, favorites do win most of the time, however, because of the odds, that would still make you unprofitable in the long run.
If you are good to go with just one shot of a bet, then bet on the underdog, but always remember that it could also lose.
But there are also fixed matches happening. Yes, most of the crowd favorites are winning the game, but sometimes if the game was fixed, they would change it to the opposite side. I agree you should not bet, but how could you enjoy and win something if you don't bet? The best solution is to bet for entertainment and bet what you can afford to lose, so it is not going to hurt in the end. In gambling, there are no risk-free games or fights. It all comes with risk, but the probability of winning is also higher.