Asked about the reason for United's late wins, Solskjaer said: "We have improved and we have been better at winning games towards the end of games.
"Our fitness now, with all the games we've had, the boys are capable of churning out 90 minutes and the fitter you are the more you can do. I have always said that. The harder you train and the harder you play, the more ready you are.
"That's the pleasure I get from winning games like this because last season we didn't have them, but this season we have done that loads and that is down to the training ground and the attitude of the players."