Reja and Mazzarri play different systems, and there's little doubt who most fans would rather have on their bench, but the Tuscan will have been a little jealous of his 68-year-old counterpart after this game.
Lazio were far from brilliant, but their players outshone their Nerazzurri counterparts in all the key areas—and that will frustrate Mazzarri.
The Inter defence was poor, while the Lazio back-line was alert and well organised.
Cristian Ledesma ran himself into the ground in the middle of the park, winning back the ball for his side and generally being a nuisance for the Inter midfield. It was the kind of performance Mazzarri needs from Zdravko Kuzmanovic or Mateo Kovacic, both of whom were poor.
Out wide, Lazio were better too. Antonio Candreva, in particular, was excellent and though Klose got the plaudits for scoring the winning goal, the German will have known who to thank afterwards. The Roman winger was hard-working, committed and creative. His opponents were not.