Suso's first AC Milan goal since November earned the Rossoneri a surprise point at the Stadio Olimpico against a tough Lazio side.
For the majority, Lazio were on top and created a host of chances, taking the lead through a Lucas Biglia late in the first half.
However, as Lazio turned the screw Milan took advantage of some slack play at the back from the home side, and Suso made his way into the opposition box, before elegantly placing the ball into the far corner five minutes from time.
As a result, the European hopes of both teams took a dent, with Lazio in sixth on 44 points, one ahead of their opponents.
A fairly even opening period looked as if it would end goalless until, on the stroke of half-time, a combination of Gustavo Gomez and Gianluigi Donnarumma tripped Ciro Immobile to give Lazio a spot-kick.
Lucas Biglia stepped up to bag his fourth penalty of the season, placing the ball left of the Milan goalkeeper.
After the break, Lazio were very much in the ascendancy with Felipe Anderson rifling just over the crossbar, then blasting another opportunity wide from close range.
Sergej Milinkovic-Savic had Donnarumma rooted to the spot as his curling effort from the edge of the area looked destined for the top corner, but it flew inches wide.
Donnarumma then managed a fantastic reaction save to stop Immobile, who had managed to get in on goal and then minutes later Suso found a yard of space in the Lazio penalty area and bent a shot into the far corner.
