The lone rest day in the Brazilian leg gave enough time to Anand to recover from an unexpected loss in the third round against Vassily Ivanchuk of Ukraine.
Although Anand`s opponent Vallejo was near to a draw, the Indian`s skills proved far superior.
Meanwhile, Ivanchuk took another giant leap forward by defeating Levon Aronian of Armenia.
With his third victory on the trot in the category-22 super tournament being played under a soccer-like scoring system, the 42-year old Ivanchuk (10 points) stretched his lead to a huge 5 points over nearest rivals Anand and Aronian.
The other game of the day between world number one Magnus Carlsen of Norway and Hikaru Nakamura of United States ended in a draw, leaving the latter at fourth spot with four points, while Carlsen and Vallejo Pons share the last spot on three points apiece.
After losing the previous game, Anand spent the off-day having Japanese lunch and a walk in the park as he prepared himself for a comeback, which many pundits had predicted.
Vallejo Pons is the lowest ranked player in the tournament and his lone victory against Carlsen had come from a much worse position.
Anand went for symmetrical set-up in the English opening and Vallejo showed some courage earlier on by looking forward to complications. However, the world champion went for an early trade of queens that gave the indication that a long battle was well on cards.