After a third-round loss at Wimbledon, Vilas rattled off a still-record 46 wins in a row, starting with a title run at the Kitzbuhel clay tournament in Austria. He then tore through the U.S. circuit, winning titles in Washington, DC, Louisville, South Orange and Columbus before beating Jimmy Connors for the title at the US Open — played on clay at the time. He then won two matches for his native Argentina in the Davis Cup semifinals, took another title in Paris and made a run to the final in Aix en Provence, where Ilie Nastase finally brought an end to the incredible streak.
Roger Federer: 41 straight in 2006-07
Federer only lost five times in 2006 — four times in finals to Rafael Nadal and once in the second round of the Cincinnati Masters to an up-and-coming Andy Murray. After that, Federer went on his record-pushing tear, winning the US Open, a couple of Davis Cup matches, and titles in Tokyo, Madrid and Basel before ending the year by claiming the Masters Cup. He then started 2007 with titles at the Australian Open and Dubai before a stunning first-match loss to Guillermo Canas at Indian Wells.
John McEnroe: 42 straight in 1984
McEnroe ended 1983 with a loss to Mats Wilander in the Australian Open semifinals. It didn't take long for him to get over it. The American star won the Masters tournament to start 1984, then won indoor tournaments in Philadelphia, Richmond, Madrid, Brussels and Dallas with a couple Davis Cup wins sandwiched in the middle. He proceeded to win Forest Hills and the World Team Cup before falling in the French Open final to Ivan Lendl. McEnroe's 42 straight wins to start a calendar year still stand as the all-time record. He would go on to finish the year 85-3.
Novak Djokovic: 43 straight in 2010-11
Djokovic ended 2010 with a pair of wins for champion Serbia in the Davis Cup final and continued to assault both the all-time win streak record and John McEnroe's mark of 42 straight wins to start a calendar year in 2011. His overall streak made it to 43, his 2011 streak to 41, before he lost to Roger Federer in the French Open semifinals. He started 2011 with a litany of high-profile titles — the Australian Open, Dubai, Indian Wells, Miami, Madrid and Rome — as well as a win in his native Belgrade. He defeated world No. 1 Rafael Nadal in four of those finals.
Bjorn Borg: 43 straight in 1978
Borg's run began in Las Vegas, where he defeated popular tennis names Rod Laver, Tony Roche, Cliff Drysdale and Vitus Gerulaitis on his way to the title. He added titles in Milan and Rome before winning Roland Garros and Wimbledon back-to-back — the first of three straight times he'd achieve that feat. He then won Bastad before losing the US Open final to Jimmy Connors. The streak featured two events played that didn't culminate in titles — in both Rotterdam and Dallas, Borg pulled out of the tournament in-between matches, which doesn't count against the streak.
Ivan Lendl: 44 straight in 1981-82
Lendl lost in the fourth round at the US Open in 1981, then went on a near-record tear in the months that followed. He won titles in Madrid, Barcelona, Basel, Vienna, Cologne and Buenos Aires to cap the year. Lendl then started 1982 with titles at the Masters tournament and in Delray Beach before losing the final of the clay tourney at La Quinta to Yannick Noah, just two matches shy of equaling the all-time record. Surprisingly, he was still over two years away from winning his first of eight Grand Slam titles.