Maria Sharapova is through to the quarter-finals of the Sony Ericsson Open after a 6-4 7-6 win over Ekaterina Makarova in Miami.
The first set between the two Russians was an even contest, with Sharapova forced into saving six break points due to some sloppy serving.
But the former Wimbledon champion put that to one side to claim the decisive break and take the first set 6-4.
There were plenty more breaks in the second as each player broke their opponent on three occasions to take it into a tiebreak.
Sharapova won that 7-3 to secure a straight-sets win, which although appearing comfortable on paper, represented a sloppy performance from the number two seed.
She will face either Li Na or Sabine Lisicki in the quarter-finals.