For a few years in the 1960s, when Grand Slam tournaments were not yet open to professionals, Mr. Ralston was regarded as not simply the best tennis amateur in America, but a prodigy who had a chance to become a World No. 1 like Don Budge, Jack Kramer and Pancho Gonzales, his onetime coach. “Mechanically, he had everything,” Kramer later told Sports Illustrated. “Oh, maybe not enough spin on his second serve, but outside of that — everything.”
Mr. Ralston was 5 when he played in his first tournament, losing to an 11-year-old near his home in Bakersfield, Calif. At age 17, he skipped his high school graduation to compete at Wimbledon for the first time, paying for his trip to England in part with $500 he won as a regional junior champion, and renting an attic flat in London for less than $2 a day.
He and his future college roommate, 21-year-old Rafael Osuna of Mexico, teamed up to defeat the British duo of Mike Davies and Bobby Wilson in straight sets in the 1960 final, becoming the first unseeded team to win the Wimbledon doubles title and the second-youngest men’s champions in tournament history.
Mr. Ralston, a 6-foot-2 right-hander with strawberry blond hair, joked that he had chosen Wimbledon over graduation because he “didn’t have a date for the prom.”
He later won collegiate titles at the University of Southern California and excelled in doubles matches, partnering with Chuck McKinley to win the U.S. National Championships in 1961, 1963 and 1964, and with Clark Graebner to win the 1966 French Championships on clay. He reached the mixed-doubles finals at a Grand Slam four times, playing with Ann Haydon Jones, Billie Jean King, Françoise Dürr and Darlene Hard.
But he also drew criticism for dropping marquee matches against lesser opponents and for losing his temper when a point didn’t go his way. Scowling and yelling at himself after minor mistakes (“You’re so bad it’s unbelievable!”), he sometimes kicked his racket and drove balls over the stands, acquiring the nickname “Dennis the Menace.”
Supporters insisted he was simply hypercompetitive — “the most competitive athlete I have ever seen,” Osuna said — and by all accounts he was gracious and courteous away from the court. “Once such a label is pinned on you, there’s not much you can do about it,” Mr. Ralston told the Associated Press in 1966.
That same year, he was ranked No. 5 worldwide and seemed on the verge of winning his first Grand Slam singles title. He defeated Cliff Drysdale in a five-set marathon in the Wimbledon semifinals, only to lose in straight sets to Spaniard Manuel Santana, in what the AP described as “one of the most memorable finals since World War II.”
Mr. Ralston was by then struggling with bad knees — he had 16 knee operations, the first when he was 18 — and turned pro soon after the match, reportedly signing a $70,000 contract for two years. “Professional tennis offers me a future,” he said, “while amateur tennis in the United States offers a player nothing.”
The landscape for young tennis players changed rapidly over the next two years. Major tournaments opened themselves to pros, and Mr. Ralston joined the World Championship Tennis tour as one of its original stars, the so-called Handsome Eight, who were credited with helping to modernize professional tennis and pave the way for the current ATP Tour.
Mr. Ralston retired in 1977, with an overall record of 260-187, but remained involved with tennis for the next half century. He led the men’s team at Southern Methodist University for more than a decade, receiving NCAA coach of the year honors in 1983; coached fellow Hall of Famers Gabriela Sabatini, Yannick Noah and Chris Evert, the longtime world No. 1; and overcame a painkiller addiction and the loss of part of his leg to continue coaching late in life.
“He was not the next Budge (or Kramer, or Gonzales) as everyone claimed. But then neither was he Dennis the Menace, which seemed just as certain,” Sports Illustrated journalist Frank Deford wrote in 1973, in the midst of Mr. Ralston’s transition from “bad boy” player to respected coach. “Ralston was less a player and more a man than anyone perceived.”
“I haven’t any regrets,” he told Deford. “Who’s to say I’d be where I am now if I’d won lots of Wimbledons and lots of money? Who’s to say I’d have my family? Who’s to say I’d be happy now? I am happy now, and I wasn’t happy then, not even when I was No. 1 and getting all the publicity. But I didn’t have any sense of direction then, and I have that now, and let me tell you, it is better than the big money.”
Richard Dennis Ralston was born in Bakersfield on July 27, 1942. His mother was a schoolteacher, and his father worked for the phone company; both parents played tennis, and set up a courtside playpen to keep an eye on Dennis during matches at a nearby park before giving him a child-sized racket of his own.
His mother once recalled that he wanted to win so badly he cried after matches, hiding behind the bushes. “But we’re both that way: We play to win,” she told Sports Illustrated. “It’s in the genes and the chromosomes.”
At USC, Mr. Ralston trained under coach George Toley, played doubles with Osuna and battled Arthur Ashe, who played for rival UCLA. He helped lead the Trojans to three straight NCAA team titles, beginning in 1962, and won NCAA individual and doubles championships in 1963 and 1964.
He also propelled the U.S. team to victory at the 1963 Davis Cup, ending a four-year title run by Australia. Nine years later, he captained and coached the team when it defeated Romania in the final in Bucharest, overcoming what Mr. Ralston later described as local linesmen who were trying to cheat the Americans out of the title.
In 1964 he married Linda Shaw. In addition to his wife, of Austin, survivors include three children, Angela Clarke of Houston, Laura Thompson of Chicago and Mike Ralston of Austin; a sister; seven grandchildren; and two great-grandchildren.
Mr. Ralston was inducted into the International Tennis Hall of Fame in 1987. He continued to play in amateur seniors tournaments, including at Wimbledon, despite persistent knee problems; while recovering from a double knee replacement, he was prescribed Vicodin in 1999, and developed an addiction after switching to OxyContin.
“Pretty soon,” he told the Dallas Morning News, “my life was run by, ‘Will I run out of pills?’ ” In need of money, he melted and sold some of his silver trophies. Surgeries on his foot were followed by infections, and in 2010 he had his left leg amputated just below the knee. He went to the Betty Ford Center later that year.
Mr. Ralston spoke openly about drug addiction, warning against a haze of painkillers that “kills your soul,” as he put it. He continued to play tennis using a prosthetic leg, returning to the court for doubles matches and teaching clinics and private lessons at Grey Rock Tennis Club in Austin.
“I don’t want to sound like a preacher or anything,” he told the Morning News in 2012, “but it’s like the Lord has been looking out for us.”