Andy Roddick savoured the year-end number one ranking over a fine meal at a Houston restaurant on Wednesday evening and will now have until next year to sit back and digest what he has accomplished.

Andre Agassi, who beat Spain's Juan Carlos Ferrero 2-6, 6-3, 6-4 in round-robin play at the ATP Masters Cup clinching year-end honours for Roddick while he dined, would no doubt tell the 21-year-old to dig in and enjoy it while he could.

Finishing the season with the number one beside their names is one tennis's rarest feats -- an achievement Agassi only accomplished once in his remarkable career.

Roddick becomes the sixth American and just the 13th player in the history of the ATP rankings to finish the year at the top of the rankings, joining an illustrious list of names that includes, Bjorn Borg, Jimmy Connors, Ivan Lendl and Pete Sampras.

Like Agassi, Gustavo Kuerten, Jim Courier, Mats Wilander and Ilie Nastase's names appear only once while fiery Australian Lleyton Hewitt, who had held top spot the last two years could not even qualify for this season's finale.

"It's an incredible accomplishment, especially the way he's done it," Agassi said. "He's sort of done it by coming on late in the year.

"He got to the semi-finals of Australian Open but was going into the summer a lot closer to 20 in the world than number one.

"For him to dominate the hardcourt season the way he did is incredible. I did that in 1995 and it just took a lot out of me.

"He's proven himself to be number one over the greatest players in the world. So he has a lot to feel proud about."

The climb to the tennis summit capped a dizzying 10 months for Roddick, who began the campaign ranked 10th in the world with many questioning if he could ever fulfil the promise predicted for him.

Roddick answered those questions with a breakout season swooping six titles, including his first grand slam at U.S. Open and is in position to become the dominant force in the men's game with or without a victory at the Masters Cup.

"The year-end number one, if I had to choose," answered Roddick, when asked if it was more important to win the year-end event or claim the year-end ranking.

"It's extremely surreal. At the beginning of the year, I just wanted to make it here."