#5 Brock Lesnar betrayed by Paul Heyman and beaten by Big Show at WWE Survivor Series
Brock Lesnar has had the longest undefeated streak among all active WWE superstars. When Lesnar debuted in the company all those years ago in 2002, he went on an 8-month unbeaten streak which eventually led to him capturing the Undisputed WWE Championship.
Lesnar, with Paul Heyman in tow, made his RAW debut the night after Wrestlemania 18, attacking the likes of Spike Dudley and Al Snow. His first major feud was against the Hardy Boyz and he defeated both brothers in separate singles matches. He did suffer a tag team defeat to the Hardys when his partner Shawn Stasiak ate the pin at Insurrextion 2003, but that was hardly brought up by the commentators.
Lesnar's streak ran through the King of the Ring tournament, which he won by beating Rob Van Dam in the finals. He would proceed to choke out Hulk Hogan next before beating the Rock for the Undisputed WWE title at Summerslam, winning the championship just 126 days after his debut.
A three PPV feud with the Undertaker ended in Lesnar's favour and after another title victory over Edge, Brock faced The Big Show at Survivor Series. It was here that Lesnar's unbeaten streak ended after Paul Heyman turned on his client. A chokeslam later, Big Show was the world champion and Lesnar's unbeaten run was over.