Bjorn Borg (May-Sept. 1978)
Nobody went on hot streaks like Borg, who won at least 29 straight on four occasions. His 1978 run included his third titles at the French Open and Wimbledon. He didn't drop a set in Paris.
Borg's streak nearly fell apart in the first round at Wimbledon. Unheralded American Victor Amaya had a two-sets-to-one lead, but the Swede ousted him in five.
After beating Jimmy Connors in the Wimbledon final, his run finally ended at the hands of Connors at the U.S. Open.