By Chris Bevan
BBC Sport at Wimbledon
Williams beat another Briton, Naomi Cavaday, in the first round
Defending champion Venus Williams was pushed hard by British number one Anne Keothavong before coming through their second-round match 7-5 6-2.
Keothavong started slowly but was soon putting pressure on the American's serve and had several chances to move ahead in the first set.
It was Williams who won it, however, by producing big shots on the key points.
And, although Keothavong continued to attack, errors crept into her game and eventually handed Williams victory.
The four-time champion was full of praise for Keothavong afterwards, and admitted she was rattled in the early stages.
"Anne played really well," Williams said. "She hit a lot of deep shots and some smart serves and did very well.
"I lost a bit of focus after making so many errors at 2-1 up in the first set but I am pleased I got it back."
Things had looked ominous for Keothavong early on when she picked up only two points in the first two games but she quickly broke back, helped by some wild shots by Williams - including a terrible attempted smash.
The Londoner, the last British woman in the singles, continued to put pressure on Williams' serve and had eight more break points at 2-2 but was unable to take any of them.
But that gave Keothavong the confidence she needed and, despite never really finding fluency with her first serve, she matched her illustrious opponent shot for shot.
Just as against fellow Briton Naomi Cavaday in the first round, it seemed Williams would be taken to a first-set tie-break but at 6-5 and 30-all she produced two raking forehands to win it.
Cavaday faded on Tuesday after her early endeavours but Keothavong did not let her tempo drop and continued to return aggressively.
Sadly she was still finding things more difficult on her own serve and Williams broke on her way to taking a 4-1 lead in the second set.
There was still time for one last push from Keothavong, who at last powered down some stinging deliveries to hold before rushing to 0-30 on the Williams serve.
But the seventh seed recovered to make it 5-2 and broke again to wrap up what became a comfortable victory.
I definitely think I could have won the first set and then who knows what could have happened
Keothavong, who had won only one match at the All England Club in seven attempts before this year, can still take encouragement from her performances this week.
After becoming the first British woman since Sam Smith in 1999 to qualify automatically for the main draw courtesy of her world ranking, she fought back from a set down to beat Vania King in the first round and deserves credit for putting up a fight against Williams.
"It was my first time on Centre Court and I didn't know what to expect until I got out there," Keothavong said.
"I really enjoyed it and I tried my hardest. These are the sort of matches I want to be playing week in, week out.
"I was right with her in the first set and there were just a few points here and there between us. I definitely think I could have won it and then who knows what could have happened.
"But she has got so much experience and she just overpowered me at times."
Williams plays Spain's Maria Jose Martinez in round three after she beat India's Sania Mirza 0-6 6-4 7-9 in an epic match.
The American admits she is not yet firing on all cylinders but is pleased to continue her progress.
"After the first two games I was feeling good but no match is predictable," Williams said. "I would like things to go my way all the time but they don't.
"I am not completely happy with the way I played but it is just about getting through to the next round."