#1 Main Event without part-timers

As mentioned earlier, the main event of WrestleMania 35 will be contested between RAW Women's champion Ronda Rousey, SD Live Women's champion Charlotte Flair, and the winner of 2019 women's Royal Rumble Becky Lynch in a "Winner Takes All' match. All three of the women involved are full-timers in the company.
However, the last time when the WrestleMania main event was contested between active workers of the company was in 2011 at WrestleMania 27 when The Miz defended his WWE Championship against John Cena.
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After that, every WrestleMania main events up to WrestleMania 35 had at least one part-timer.
The Rock competed in the main event of both WrestleMania 28 and 29. Batista challenged Randy Orton in the main event of WrestleMania 30. Brock Lesnar was the defending champion during the closing match of both WrestleMania 31 and 34. Triple H was the defending champion at WrestleMania 32, and the Undertaker was in the main event of WrestleMania 33.