A lot of tire saving here was due to the tires falling off the cliff in Canada and a few races before trying to stick with the faster cars so this time around he gradually (and very conservatively) brought the pace in. I think what he didn't expect was the car to keep the tires alive so when he upped the pace the car kept up with it and kept going faster. Same for the Hard tires. Alonso experimented again and once the tires bedded in he was unstoppable.
I think more than the race results this is what made Alonso happy and excited cause the car is now working well. If the car is fast in Sector 3 in Hungary, It will be fast everywhere because that sector decides how well the car keeps it's tires and can corner well. This is why no own apart from Norris could overtake Alonso cause they couldn't keep up.
They still need to figure stuff out cause although tire saving the first few laps was still very bad but i think there are now just one step aways from solid results at every GP.