Ben Spies admits missing out on victory in the first World Superbike race of the day at Monza was a 'tough pill to swallow', but he was delighted to make amends with victory on the second attempt.

Spies should have come away from Italy clutching a double victory, but he was left to coast across the finish line an immensely frustrated 15th when he ran out of fuel on the final corner of the opening race whilst leading.

A disappointing outcome to what had been a strong performance for Spies, who had fended off the attentions of Michel Fabrizio and Noriyuki Haga throughout the race, the American remained philosophical about the error.

"That was a tough pill to swallow," he said. "You can only carry so much fuel, and this is a long track and we run at full throttle so much that unfortunately we ran out at the end."

Nonetheless, Spies more than made amends in race two, leading from almost start to the finish, even if he admits he approached the race a little differently to avoid a repeat of his race one problems.

"I definitely rode the warm up laps differently and short-shifted the bike late in the race to make sure I could make it to the finish," he added. "The bike could have run faster the entire race, but I wanted to make sure we brought it home. The Yamaha guys regrouped after race one, figured things out and it was great to end the weekend on a high note."

With title rival Noriyuki Haga failing to finish after crashing out of contention on lap three, Spies has managed to reduce the gap to his rival to 54 points.

"Hopefully Nori is OK. Having him suffer a crash is not the way I'd hope to stay in the championship."