(Reuters) - A second-place finish at the U.S. Grand Prix in Austin on Sunday appeared to energise Lewis Hamilton with the Mercedes seven-times world champion saying that when his team builds a more competitive car he will take it to the top.With just three races remaining for the first time since entering Formula One in 2007 Hamilton is in danger of finishing a season without a victory which would add to what has been an annus horribilis for Mercedes, who watched rivals Red Bull clinch the constructors title they had owned for eight years.But there was hope not despair around the Mercedes garage on Sunday after a battling Hamilton engaged in a breathtaking duel with Red Bull's double-world champion Max Verstappen over the final laps before surrendering victory to the Dutchman."We are much closer now, the upgrade worked and we were racing for a win," said Mercedes boss Toto Wolff. "I think we understand more now what it is where we got it wrong with the car. "We thought we can run the car on the deck but you can’t so it's small little hamster steps and as long as the trajectory is going up I think we are on a good path."Hamilton has had two other runnerup results this season in France and Hungary but it was the manner of the fight in Texas that had both the Englishman and his Mercedes team looking ahead to next year."What's happened this year in terms of our performance and everything to get a win would be a huge triumph for us," said Hamilton. "But what I think of from today we had good pace, I'm still here and I know that when they build the car I will take it to the top. "So we just have to keep working."Verstappen seized the lead into the first corner and was in control when he made his second stop on the 36th of 56