Serena Williams proves the show’s not over with impressive US Open victory

• 23-time major champion beats Danka Kovinic 6-3, 6-3
• American has suggested she will retire after tournament
• As it happened: Beau Dure's game-by-game report

Serena Williams has extended her presumptive farewell tour at least two more days.

The 23-time major singles champion overcame early nerves and a misfiring serve to win 6-3, 6-3 against Danka Kovini in their US Open first-round match at Arthur Ashe Stadium, launching what is expected to be the final tournament of her glittering 27-year professional career on a winning note.