Top-seeded Maria Sharapova, who had eight double faults, lost in 58 minutes at the Sony Ericsson Open

It was less a match than a memorandum of what Serena Williams is capable of when she puts her mind behind her might. Covering the court like a tarp, Williams suffocated top-seeded Maria Sharapova in 58 bloodless minutes Tuesday in the fourth round of the Sony Ericsson Open.The final score was 6-1, 6-1, and from high above Crandon Park’s Stadium Court, it looked more lopsided. Before the first point was tallied, Sharapova seemed to sense that she was in for a long afternoon. She kept hitting serves after the chair umpire called, “Time,” indicating the end of warm-ups. Whatever she was searching for, Sharapova did not find it, committing eight double faults.On the other side of the court, the 13th-seeded Williams was hitting on all cylinders. Her ground strokes were so grooved that Sharapova seemed to be swatting at bugs. In the sixth game of the first set, Sharapova hit a running forehand for a winner (one of eight she had) and Williams was so surprised she reflexively applauded.By the end of the afternoon, both No. 1-seeded players were gone. Guillermo Cañas, a qualifier, sent the defending champion, Roger Federer, packing for the second consecutive tournament with a 7-6 (2), 2-6, 7-6 (5) victory. Cañas’s win came 16 days after he snapped Federer’s 41-match winning streak in a second-round match at the Masters Series event in Indian Wells, Calif. Federer, who had won both tournaments the previous two years, committed 51 unforced errors to Cañas’s 15.“You know, it happens,” Federer said. “I was really happy with my level of play. I thought it was a great match, so it was disappointing to lose.”Williams was delighted to win as emphatically as she did. With every stroke, she seemed to be issuing a rebuttal to those who openly wondered if her 6-1, 6-2 victory against Sharapova in the Australian Open final had been a fluke.“I think a lot of people might have thought it was a one-off,” said Williams, who played in only four tournaments in 2006 because of injuries. “I don’t know anyone who’s won eight Grand Slams and had so many doubters in their lives. I guess just me.” She laughed ruefully. “It’s O.K.”Williams can play the media as if they were another opponent, showing humility, hostility, humor, warmth, eloquence and indifference all in one 15-minute interview. The chip on her shoulder is not an affectation but another accessory, along with the heavy hoop earrings and gaudy gold jewelry and designer handbags, that she seldom leaves home without.She uses every slight — real and perceived — to her advantage, channeling her feelings of hurt and rage into her tennis.Williams’s sense of being a perpetual outsider despite everything she has achieved in tennis was driven home to her Monday afternoon in her match against Lucie Safarova when a heckler in the stands peppered his diatribe with a racially derogatory term.The fan was escorted from the grounds, but not before everybody within earshot got a sense of how discomfiting it can be to walk in Williams’s sneakers. Her sense of alienation bubbled to the surface Tuesday when she was asked about a trip she took last year to Africa.Williams, who was born in Michigan and raised in California and Florida, toured Senegal’s Goree Island on the west coast and visited impoverished villages in Ghana as part of a Unicef delegation.“When we first landed, we had a layover in Nigeria, and I couldn’t wait,” Williams said. “I wanted to get out of the plane and just take off my shoes and start running and never come back because I just felt at home and at ease.“I mean, I’ve never felt so comfortable physically and just like mentally,” she added. “I can’t even explain it. It’s like this whole aura that just surrounds you. That’s just how I felt. I’ve never been in a place where I felt happier ever.”Williams’s voice, which had been a monotone when she was talking about tennis, grew more animated as she talked about opening a school in Senegal on land donated by the nation’s president, Abdoulaye Wade, whom she met.“If I can provide one kid with hope,” Williams said, “even if it’s just one person, it makes a whole big difference in life.”In the hallway outside the interview room, Williams’s father and coach, Richard, talked about how sad it was that his daughter should feel more at home abroad, but he said he was not surprised. “Americans here don’t think we are Americans,” he said.“If we are Americans, we sure aren’t treated like it,” he added. “Rats, roaches, even rabbits are treated better than we are here.”When he was done speaking, Richard Williams walked out to the players’ valet parking area and, surrounded by luxury sedans and expensive sports cars, he lighted a cigarillo and smoked it.