In the 1st round of the 2007 Australian Open, Murray was leading Alberto Martin 6-0 6-0 5-0*, before Martin held serve in the 18th game to prevent a whitewash.
In the 1st round of Wimbledon in 2009, the world no. 64 Leonardo Mayer was leading the world no. 75 Oscar Hernandez 6-0 6-0 3-0*, before Hernandez held serve 3 consecutive times to avoid complete humiliation. Of course Mayer is more well known recently for being the victim when Young ended his recent 17 match losing streak at Winston-Salem in August.