San Francisco - Top seed Venus Williams fended off a spirited challenge in her opening match against world No 87 Magda Linette at the WTA Tour's Stanford tournament on Wednesday, as she needed three sets to advance.
Former two-time champion Williams defeated Linette 6-3, 6-7 (6/8), 6-2 to reach the quarter-finals of the hardcourt tournament at Stanford University.
The 36-year-old Williams is hoping she doesn't suffer a post-Wimbledon letdown and she now has an easy path to the semi-finals since her next opponent won't be ranked in the top 200 in the world.
Williams will face either Catherine Bellis, who is ranked 203rd, or Sachia Vickery who is one spot back of Bellis in the world rankings.
"It would be very special to get No 50 here but I am just going to try to keep advancing," said Williams, who has 49 career titles after winning in Kaohsiung, Taiwan earlier this year.
Williams blasted 11 aces and had four double faults against Linette in the two hour, 14 minute match on the main stadium.
Earlier this month Williams reached the semi-finals of Wimbledon, her first semi at a major in five years.
Williams played her first professional tennis match at this event in 1994 and she has won here twice but not since beating Kim Clijsters 14 years ago.
The former world No 1 has seen her game fall on hard times over the past several years.
And she got off to a rocky start to this season before recovering, losing in the first round of the Australian Open to the 47th ranked Johanna Konta.
To add insult to injury, organizers fined her a record $5 000 for refusing to attend the post match news conference. She also suffered losses in opening second round matches at both Miami and Indian Wells.
Linette, who is ranked second in Poland behind Agnieszka Radwanska, had to be pleased to take the world No 7 to three sets in her Stanford debut.
In 2015 she made her Grand Slam debuts at the French Open, US Open and Wimbledon.
In other matches, fifth seeded Misaki Doi showed no mercy against her Japanese doubles partner Nao Hibino, winning in straight sets 6-3, 6-4 in their second round match.
Doi, who is ranked 36th in the world, advances to the next round where she will face either second seed Dominika Cibulkova or Urszula Radwanska of Poland.
Doi is hoping that a good run through the rest of the summer will help her earn a seeding spot for the upcoming US Open.
Doi defeated Karolina Pliskova in Wimbledon's second round, forced Sam Stosur to play three sets in a first round loss at the French Open, and gave Angelique Kerber a scare at the Australian Open earlier this year, taking the eventual champion to match point in the early rounds.
British No 1 Konta took care of business, beating Julia Boserup 6-3, 6-1 in just over an hour.
Her Stanford debut continues in the quarter-finals where she will face China's Zheng Saisai, who upset seventh seeded Frenchwoman Alize Cornet 6-4, 6-1.
Results from the second round on the third day of the WTA event in Stanford, California on Wednesday (x denotes seeding):
Zheng Saisai (CHN) beat Alize Cornet (FRA x7) 6-4, 6-1
Johanna Konta (GBR x3) beat Julia Boserup (USA) 6-3, 6-1
Misaki Doi (JPN x5) beat Nao Hibino (JPN) 6-3, 6-4
Venus Williams (USA x1) beat Magda Linette (POL) 6-3, 6-7 (6/8), 6-2