- Pedro (13')
- Sergej Milinkovic-Savic (56')
"We have three important points in a race that is still very long," Sarri said.
"There are 30 points up for grabs, we were able to catch up on the others in a short period and the reverse can easily happen too."
Pedro scored the opener 12 minutes into the game, taking advantage of poor defending from the home side to find space in the centre of the box and effortlessly slot home.
"Monza are a good team, but I think we did a good job and ended up with a good victory," Pedro told reporters. "Now we are good in the standings, there are 10 games left but we must continue like this"
Lazio doubled their lead in the 56th minute with a superb free kick from Milinkovic-Savic that went into the top left corner, beyond the reach of keeper Michele Di Gregorio.
The Serbia international became the top-scoring foreigner in Lazio's history, reaching 65 goals since joining the club in 2015.
"Finally, I managed to score and I really missed that feeling. There has been a lot of criticism, now this goal will give me a big hand," Milinkovic-Savic, who scored for the first time since January, told DAZN.
"These are three big points for us, as we are still in second place for a while longer."
- Matteo Marcenaro