The former beat Taylor Dent while Fish edged out Chilean Fernando Gonzalez in the semi-finals.
The double Olympic gold medallist whipped Jose Acasuso of Argentina for the loss of just six games at the US Open.
Olympic gold medallist Nicolas Massu pulled out of the Australian Open after aggravating an ankle injury in the second round.
The Chilean added the men's singles gold to the doubles crown he won on Saturday after beating Mardy Fish in the final.
The Olympic singles and doubles champion beat Alberto Martin of Spain in the final.
The double Olympic champion was seething after losing to Sargis Sargsian in the second round of the U.S. Open.
Chile's double Olympic champion Nicolas Massu advanced to the second round of the Auckland Open with a 6-4 6-2 victory over New Zealand qualifier G.D. Jones as persistent rain prevented much of Tuesday's play.
Igor Andreev beat Nicolas Massu in the final rubber of their first round Davis Cup tie to seal a hard-fought 3-2 victory over Chile.
Federer played a more aggressive game than the Spaniard but 27 unforced errors cost him a place in the final .
Unseeded Chilean Nicolas Massu brought Andy Roddick's 20-match unbeaten Tour run to a crashing end.
The Indo-Belarussian pair will play Wayne Black and Kevin Ulyett in the penultimate round of the BNP Paribas ATP Masters tournament.
Somdev Devvarman's struggle on the ATP circuit continued as the fifth seed Indian crashed out of the Zagreb Challenger event after suffering a first round defeat against unseeded Yuri Schukin.
Former world number one Juan Carlos Ferrero advanced to his first Auckland Open final with a 6-3, 6-4 victory over France's Julien Benneteau on Friday.
Russia's Dmitry Tursunov was ruled out of the Davis Cup tie against Chile with a wrist injury.
All the World Group first-round ties are still alive heading into the final day's singles after the underdogs largely prevailed in some lengthy doubles clashes.
Former world number one Marat Safin set the Russians on their way with a straight sets victory over Olympic champion Nicolas Massu before Igor Andreev upset world number five Fernando Gonzalez in four sets.
Roger Federer and Rafael Nadal returned from vacation to post first-round wins at the Toronto Masters.
Both were knocked out of the men's doubles in the second round at the Rome Masters.
The former French Open champion rolled back the years as he dumped fifth seed Nicolas Massu out of the Estoril Open on Wednesday.
The Indo-Belarussian pair beat Andrei Pavel of Romania and Nenad Zimonjic of Serbia Monetnegro in straight sets in the first round of the Paris Masters.
The two seeded players went down in the quarter-finals of the Olympic men's tennis tournament.
The top seeds lost to seventh seeds Gaston Etlis and Martin Rodriguez of Argentina in the quarter-finals of the Monte Carlo Masters.\n\n
The Spanish teenager reached the second round of the Estoril Open even as second seed Nicolas Massu of Chile bowed out.
"It was special to win in front of my home fans," Ferrero said after clinching victory in two hours 30 minutes.
Andy Roddick beat Nicolas Massu after Fernando Gonzalez stunned James Blake in the Davis Cup quarter-final.
Rafael Nadal withdrew from the Indian Wells tournament on Saturday with a knee injury, shortly before his eagerly-awaited semi-final clash with great rival Roger Federer.
Here are eight men to watch on the Roland Garros clay.