Seven-time champion is joined in next round by sister Venus, but there was a shock defeat to Wozniacki, while over in the men's draw Federer marched on
Serena Williams 'going in the right direction' after strolling into Wimbledon third round
Serena Williams said she is still improving after booking her place in the third round of Wimbledon on Wednesday with a 6-1, 6-4 win over Bulgarian qualifier Viktoriya Tomova.
Williams, a seven-time champion at the All England Club, is playing in just her fourth event of the year as she eases her way back into competitive tennis following a lengthy time away to give birth.
The 36-year-old American, who was named 25th seed for the tournament despite a world ranking of 181, needed just one hour and eight minutes to dispatch Tomova on Centre Court.
"It was better than my first round and I'm happy that I'm going in the right direction," said Williams, who took her winning streak at Wimbledon to 16 matches. "I'm getting there. I expect to get there, not only for Wimbledonbut for the tournaments in the future."
Williams will face another step up in quality in her third round match when she takes on either Frenchwoman Kristina Mladenovic, who reached a career-high No 10 in the world rankings last season, or Germany's Tatjana Maria, who defeated fifth seed Elina Svitolina in the first round.
Williams is joined in the third round by older sister Venus, who fought back from a set down to defeat Romania's Alexandra Dulgheru 4-6, 6-0, 6-1.
While the Williams sisters rolled on, second seed Caroline Wozniacki crashed out following a surprise 6-4, 1-6, 7-5 defeat to Russian Ekaterina Makarova.
Wozniacki, plagued by an invasion of flying ants during the Court 1 clash, saved five match points but has now failed to get past the fourth round in 12 visits to the All England Club.
Russian world No 35 Makarova faces Czech world No 66 Lucie Safarova, who defeated former finalist Agnieszka Radwanska 7-5, 6-4, in the third round.
"I couldn't win with a lot of match points, but I kept fighting and playing an aggressive game and finally it worked," said Makarova, who had lost seven of her previous eight meetings with Wozniacki. "I was really nervous, because you need to win this point.
"When it was 5-5 I started thinking about those match points on my serve at 40-0. But I told myself 'no, you are not going to lose this match'. I forgot it and started over."
Czech seventh seed Karolina Pliskova came through a tricky encounter against two-time Australian Open champion Victoria Azarenka.
In the men's draw, Roger Federer extended his Wimbledon winning streak to 26 consecutive sets as the defending champion crushed Lukas Lacko.
The Swiss top seed hit 48 winners and 16 aces in his 6-4, 6-4, 6-1 victory, and is now on his joint-second longest streak of sets won at Wimbledon - his best was 34 between the third round in 2005 to the 2006 final.
Next up for eight-time champion Federer is a third round tie against German world number 64 Jan-Lennard Struff who came back from two sets down to defeat 39-year-old Ivo Karlovic 13-11 in the final set.
"I played very well. I felt good out there, less nerves than in the first round," Federer, 36, said. "I'm happy how I am hitting the ball, good concentration on my service games and able to mix it up with some slices.
"Of course, you sometimes play the percentages, but if you do that too much it becomes boring, so I like to mix it up."
Milos Raonic, the 2016 finalist, booked his place in the third round with a 7-6, 7-6, 7-6 win over Australian John Millman. Raonic has been struggling with injuries this season and after retiring from his second round match at Queen's, there were concerns about his participation at Wimbledon.
However, the Canadian 13th seed has been nearly faultless on his fearsome serve over two matches at Wimbledon so far, getting broken just once. He will take on Austrian qualifier Dennis Novak, who produced the shock of the day to defeat French 17th seed Lucas Pouille 6-4, 6-2, 6-7, 3-6, 6-2.