BEIJING, China - In an intriguing first-round clash of unseeded players at the China Open, Venus Williams survived a comeback from Barbora Strycova before essaying her own recovery from the brink of defeat, triumphing 6-3, 4-6, 7-5 in two hours and 31 minutes.

The result extends Williams's unbeaten record against the Czech to five wins in five encounters - and is her third of those to see her come through a nailbiting final set. This time, the former World No.1 was unable to press home a big lead after holding two points for a set and a double break - but survived Strycova serving for the match in the deciding set to reel off the final four games in a row.

Initially, Williams dominated proceedings with solid aggressive tennis. Swarming the net at every opportunity, striking her forehand with relish and moving smoothly around the court, the American would not face a break point over the course of the first set. Winning 78% of her first serve points, Williams effectively smothered Strycova's attempts to inject change-ups into the rallies; the Wimbledon semifinalist's dropshots frequently sat up to be smacked away, and her forehand in particular let her down as she committed 16 unforced errors to only four winners across the opening act.

Loose errors off that wing would pave the way to the only break of serve in the set in the sixth game for Williams, who went on to seal the set with a ferocious off forehand winner before riding her momentum into the second set to immediately capture the Strycova serve in the first game.

Williams seemed to have successfully navigated a crucial passage of play as she came up with some of her finest shots to save a break point and hold for 3-1, sealing the game by flicking a spectacularly athletic high backhand volley past her opponent. But, facing two points to fall behind a double break at 2-4, Strycova belatedly lifted her level for a remarkable fightback.

Displaying fine net play of her own, the 33-year-old clung on to the hold before blitzing a pass past Williams en route to breaking back. As the former World No.1 began to leak errors, Strycova rattled off five straight games to level the match and take her momentum into the decider.

It was Williams who struck first in the third set, breaking for 3-2 as Strycova's forehand went awry again, but the lead didn't last long: the 39-year-old's backhand was also misfiring, and Strycova took advantage to break back with a forehand winner down the line. Demonstrating vastly improved touch on the dropshot, the World No.34 put together another three-game streak to move up 5-3.

Strycova would twice come within two points of victory, once in each of the next two games - but with her back to the wall, Williams was clutch. A booming backhand return saw her break back - and, having levelled the score with three consecutive service winners, a finely judged lob put the World No.59 back in front.

Serving for the win, an eighth double fault delayed the win for Williams on her first match point - but on her second, the seven-time major champion came out on top of a high-octane baseline rally to book a second-round spot against No.9 seed Belinda Bencic.