Serena Williams survived another scare to beat older sister Venus 3-6 6-3 6-4 on Thursday in the latest instalment of their reluctant on-court sibling rivalry.
The win helped her to reach the quarter-finals of the inaugural Top Seed Open in Lexington, Kentucky.
Serena, who in her first-round match of the spectator-free tournament was five points from defeat against world number 60 Bernarda Pera, however had much work to do to survive.
She had to rally back from a set down and 4-2 final set deficit to prevail in a thrilling battle.
With the win, Serena improved to 19-12 in career head-to-head meetings with Venus.
“It was a very high quality match,” said Serena.
“There was a lot of long points, running me around and then at one point it was just big serves and so I thought that was really interesting as we both started serving really well and returning well.”