By the age of 16 he had earned a 100-ton motorsailer vessel pilot's license and was acting as chair umpire for finals of international tournaments in Buenos Aires.

In Rio de Janeiro Wegner practiced tennis with Lucy Maia at Fluminense Football Club, attended soccer matches and fell in love with the country.

He returned on several occasions to enjoy the city, visit friends and play tennis with locals such as Jorge Paulo Lemann and coach Pepe Aguero at the Country Club of Rio de Janeiro.

The challenge of traveling around the world with the small budget of a few hundred dollars of "under the table" expenses paid by the tournaments was very exciting to the young Wegner, and in five years he visited over 30 countries and met numerous top players and local personalities.

[citation needed] His friendship with top players, including Manolo Santana, Roy Emerson and Martin Mulligan, helped him come in contact with tournament directors and receive invitations to participate.

The proposal, which was passed by an overwhelming majority and against the wishes of Australia, the US and Great Britain, specified that the finals would be played on alternate home and away locations (a rule which was common to the rest of the world).

Beginning in 1966 the finals of the Americas Zone were played under the revised rule, which may have resulted in the USA losing on red clay in Porto Alegre, Brazil in 1966 and in Guayaquil, Ecuador in 1967.

Staying behind while the other players moved on to Caracas, he later traveled to Mexico City, the second-to-last stop on the Caribbean circuit, to say goodbye to his friends and colleagues.

After leaving the tour in 1967 Wegner traveled to Los Angeles and arranged tournaments in the Caribbean and Latin America for George MacCall, then USA Davis Cup Captain and Owner of the National Tennis League (NTL), which had 6 players and 2 alternates under contract: Laver, Emerson, Rosewall, Stolle, Gimeno, Gonzales, and Segura and Olmedo.

In the Summer of 1969 Wegner taught at the Westside Tennis Club, home of the USLTA National Championship (now the US Open) in Forest Hills, New York as Assistant Coach to fr:Warren Woodcock.

While there Wegner persuaded the national coaching team including Joaquin Moure that reinforcing open stance and topspin was the best way to develop their juniors into players of international stature.

According to Bud Collins, who met Oscar Wegner in 1973 in Miami Beach where he was coaching the Spanish Junior boys team in the worldwide Sunshine Cup tournament: "Those kids were hitting extra hard and with plenty of topspin in a way that startled spectators – and me.

"[9][independent source needed] In 1974, he left Spain to take the position of Head Pro at the Aventura Country Club in North Miami Beach.

"[10] After spending 4 months in Germany Wegner returned to Florida and worked as Owner and Head Pro of the American Tennis Academy in Sunrise for the next 3 years.

[12] For the next 4 years he visited Florianópolis and Itajaí often, coaching Kuerten and many other players including Márcio Carlsson, Maria Fernanda Alves and Rita Cruz Lima at ASTEL and Itamirim Clube de Campo.

He also helped them with their games during their visits to US tournaments including the Orange Bowl for the next several years, with the exception of Guga, who started working with Larri Passos from 1990 onwards.

[citation needed] The following year Bud Collins traveled to Moscow for the first Kremlin Cup and was asked by Russian coaches for more copies of Oscar Wegner's book.

In January of that year Wegner coached Björn Borg for a month at The Colony and the Nick Bollettieri Tennis Academy in Sarasota and Bradenton, Florida.

Mike Daley introduced Wegner to Richard Williams during a satellite tournament at the Patricio Apey Tennis Academy in the Miami Airport Marriott in January 1999, and according to Oscar: "He greeted me with a great smile and said 'Oscar, it is an honor to meet you.

'"[citation needed] From April 1994 to December 1999 Wegner, who speaks 5 languages, worked for ESPN International as a tennis commentator in Spanish for Davis Cup, ATP and WTA tournaments including the Australian Open and the French Open, and in 2000 he joined the es:Panamerican Sports Network doing ATP and WTA tournaments including Wimbledon.

Also contributing to Wegner's worldwide recognition were 40 "Play Like The Pros With Oscar Wegner" Tennis Tips, instructional vignettes both in English and in Spanish, which were broadcast by ESPN International from June 1997 through September 1999 several times daily in more than 150 countries around the world, including airings during the Super Bowl, NBA Finals, Stanley Cup Finals and US Open Golf Tournaments, generating over two billion impressions on television worldwide.

Thanks to his keen eye and experience on the tour he was able to distinguish between the "modern" method referred to by Bill Tilden[15] and the traditional techniques and so-called conventional wisdom of tennis instruction, and set out to devise a more effective approach.

In the 2008 Quickstart tennis practice and play plans manual, the forehand is illustrated with an open stance and finish over the shoulder and advises that "coaches who work with young players at the start of their tennis careers will recognize the importance of starting them off well and with success",[17] while the 2009 USTA Quickstart teaching manual for parents and recreational coaches illustrates the forehand with a traditional closed-stance position with the racket finish toward the target.

Wegner has written several articles for TennisOne, a leading tennis instructional site since 1996 "founded on the dream of bringing the best teaching pros around the world to everyone.

"[20][21][22][23] In an introduction to one of his articles the editors of TennisOne wrote: "A lot has been written about the modern forehand with its natural movements, open stance, windshield-wiper swing, and most importantly, tracking the ball and waiting before taking the racquet back.

"[29] During his introduction of Wegner at the 2011 USPTA Nor Cal Annual Convention Dick Gould remarked: "Sometimes you listen to things a little different from what you've done before and Oscar and I go back a number of years...get to know him a little bit...to talk to him.