After the race he confirmed he will compete in Wales's colours at the Commonwealth Games in March, but said that his major aim will be to win the European Championship gold medal in Gothenburg next August.
The 23-year-old former World Youth 200m gold medallist - who realised as a teenager he was better suited to the one-lap event - is also adamant that he can smash the eight-year-old UK record of 44.36. That tough mark belongs to fellow Welshman Iwan Thomas, the last Briton to win the European title, in 1998, the year in which he was also crowned Commonwealth and World Cup champion.
"Tonight suggested I can run another 0.25sec quicker," he said after finishing half a stride and 0.05sec behind Tyree Washington of the US.
Benjamin missed a month's pre-season training after an injection to alleviate back pain went wrong and he found himself in hospital. "I didn't think I was going to make it," he admitted. "I was so injury-prone, I thought this was going to be a year I would miss running."
Instead, Benjamin brought the curtain down on his season by just missing out on a first major global title. He again defeated Jeremy Wariner, the American falling back to last after the pair accidentally brushed hands 50 metres from the line, forcing the Olympic and world champion to a virtual halt.
Claiming Wariner's scalp for a second time was another sign of progress for Benjamin. He beat Wariner at Crystal Palace seven weeks ago to win in 44.75, and produced the best performance of his career here, in the Stade Louis II, just missing out on the $30,000 first prize (£16,315) when shaded by Washington.Reuse content