Serena overcomes Bertens to keep Steffi Graf in sight
The defending champion was given a good game by the unseeded Dutch player but eventually prevailed as she closes in on Grand Slam record.
Serena Williams overcome the gritty challenge of unseeded Dutchwoman Kiki Bertens 7-6(7) 6-4 on Friday to reach the French Open final, putting the world number one just one match away from a record-equalling 22nd grand slam singles title.
Williams, who won the first of her three Roland Garros crowns in 2002, survived a first-set scare for the second day running, saving two sets points before winning the tiebreak.
With the Philippe Chatrier show court still little more than half full as unseasonably cold weather kept thousands of ticket-holders away, the drama continued into the second set, when Williams was broken again to trail 2-0.
But she broke straight back and conceded just two further games to reach Saturday's final, where she will face Spanish fourth seed Garbiñe Muguruza hoping to equal Steffi Graf's grand slam singles record.