Karl Beckenbauer lost his front wing early on after hitting the back of Enrique Ruiz's Franklin, but the Brazilian would soon join the German in a fight back through the field after Judson Sikes pulled across on him down the start finish straight, breaking Ruiz's own front wing.
As the field settled in, the Rettifilo chicane became the place to be with overtake after overtake happening around the outside of the first corner, while the order changed as the pit stops began. Of the leading quartet Powers, Klaas and Tumo Kinnumen were on mediums, but Finn Schnyder was on the Hards, and the Swiss driver duly inherited the lead as his rivals pitted.
The Downton pair wasted no time in reeling off fastest laps in hot pursuit but as has happened before this season Klaas made an error by spinning off at the Parabolica and handed third to Kinnumen. Schnyder eventually pitted on lap 29 and slipped to fourth, but was in a great place with no stops left to make as Powers re-took the lead.
It wasn't to last however, as contact with Will Hoskins while lapping the AMR driver on lap 32 cost both cars a wheel, and saw both retire from the race, handing the lead to Kinnumen. Klaas closed on the Finn but was unable to overtake, and couldn't take advantage in the pits either as both made their second stops on lap 37, with Schnyder re-taking the lead with no stops left to make.
Fresh tyres gave Klaas a new sense of urgency however. The Dutchman set fastest lap on his first flying lap out of the pits, and duly swept around the outside of Kinnumen at turn one on lap 40 to take second place. Schnyder was long up the road however with only fourteen laps to go, but Klaas was closing rapidly until more drama struck on lap 46.
Elroy Wagner and Enrique Ruiz collided at the Parabolica, turning the German around and into the path of James Harding, who was unable to avoid running into his team mate. Arden Hutchinson, Olen Inman, Stuart Harrison, Hugh Dwyer and race leader Schnyder were all unable to avoid the stricken Lopez, with the damage suffered forcing all but Hutchinson into retirement.
Klaas inherited the lead once again with 7 laps to go - which he duly held to the flag - while Kinnumen came home runner-up with Oleksandr Zozulya completing the podium after a quiet but impressive race to third. Like Schnyder, Puccio Giodano and Lewis Ellington also made their hard tyre strategies work by finishing fourth and fifth, the latter have earlier completed an impressive double-overtake on Giodano and Adrien Simon around the outside of turn one as the trio went three-wide.