LONDON — Last year's runners-up were up first on the main showcourts at Wimbledon on Tuesday, and both came through in straight sets. Angelique Kerber, playing in the spot on Center Court normally reserved for the defending women's champion, beat Irina Falconi of the United States 6-4, 6-4. On No. 1 Court, Milos Raonic defeated Jan-Lennard Struff of Germany 7-6 (5), 6-4, 7-6 (4).

"A lot of memories came back when I walk on the Center Court," Kerber said. "Playing there again, it's one of the best courts to play. It's traditional, so it was really great to being back."

Novak Djokovic and Roger Federer, who own a combined 10 titles at the All England Club, didn't even need three sets to advance. They both reached the second round when their opponents retired from their matches in the second set.

Kerber stepped in to the opening spot on Center Court on Day 2 in place of Serena Williams, the defending champion who is out for the rest of the season because she is pregnant.

Although Kerber became the first women seeded No. 1 in the professional era to lose in the first round of the French Open, she made it through to the second round on the grass.

"Playing first rounds in Grand Slams are always tough, especially with my first-round match that I lost in Paris," Kerber said. "I was actually just thinking about point by point, trying to finding my rhythm during the whole match."

Djokovic followed on Center Court, leading 6-3, 2-0 when Martin Klizan stopped because of injury. The second-seeded Serb was leading 30-0 in the third game of the second.

"It's really odd that Roger's result and my result more or less was the same," Djokovic said. "We had a little joke about it in the locker room, saying we should maybe play a practice set on the Center Court, have the crowd stay. But they had another match."

The victory put Djokovic alone into second place on the list of Grand Slam match wins, one ahead of Jimmy Connors, with 234. Federer, an eight-time champion who followed on Center Court and beat Alexandr Dolgopolov, leads the list with 315. Federer was leading 6-3, 3-0 when Dolgopolov retired.

There were plenty of records for Federer to savor on Tuesday as he began his pursuit of a record eighth Wimbledon title, but he was denied a chance to celebrate them in style as his first round match ended abruptly midway through the second set.

Federer's encounter against Ukrainian Dolgopolov lasted a mere 43 minutes. Fans who had poured in to see the Swiss master in action witnessed him fire down a 10,000th career ace and chalk up a record 85th win at Wimbledon, surpassing the benchmark he had shared with Jimmy Connors.

By simply playing the first point, Federer also drew level with Fabrice Santoro's professional era record of playing in a 70th grand slam tournament. While it is always nice to reach such landmarks, Tuesday's result is likely to mean only one thing for the 18-times grand slam champion — he is now only six wins away from becoming the first man to hoist the Challenge Cup for an eighth time.

Raonic came into Wimbledon after playing only one match on grass, a first-round loss at Queen's. The last time he failed to win a match on grass prior to Wimbledon, in 2014, he reached the semifinals. Last year he did even better than that, reaching the final at the All England Club and losing to Andy Murray in straight sets.

Raonic said he made good use of his time since that loss at Queen's, however. "Spent a lot more time training," Raonic said. "Sort of got to the point where I was spending a lot of days practicing. I was just getting more and more eager for this tournament to start because there were a lot of days in a row."

Juan Martin del Potro needed seven match points, but he also advanced, beating Thanasi Kokkinakis 6-3, 3-6, 7-5 (2), 6-4. Other winners include 2015 Wimbledon finalist Garbine Muguruza among the women, and 15th-seeded Gael Monfils among the men.

Caroline Wozniacki overcame a second-set wobble to book her spot in the Wimbledon second round on Tuesday. The Danish fifth seed beat Hungary's world No. 42 Timea Babos 6-4, 4-6, 6-1 in an hour and 42 minutes on Centre Court.

The former world No. 1 will play either Bulgaria's Tsvetana Pironkova or Italy's Sara Errani in the round of 64. "I just kept fighting for every point. I was down a break early in both sets. Somehow I managed to pull it out," Wozniacki said.

"I feel like I'm in good shape but the first round is always tricky. She definitely gave me a lot of competition. I love playing on Center Court. It's a very special feeling to be out there. I love playing on grass and I love Wimbledon. I'm happy to be through and hopefully I can get some good recovery."

Wimbledon is the only Grand Slam where Wozniacki has failed to reach at least the quarterfinals.

After all the hard work and dedication it takes to get to Wimbledon, at least one player couldn't be bothered with actually trying to win.

Bernard Tomic, a 24-year-old Australian who reached the quarterfinals at the All England Club in 2011, said Tuesday he "just couldn't find any motivation" to compete this year.

"I felt a little bit bored out there," Tomic said, "to be completely honest with you." Tomic was playing at Wimbledon for the eighth time. He lost to Mischa Zverev 6-4, 6-3, 6-4 on Court 14.

"I feel holding a trophy or, you know, doing well, it doesn't satisfy me anymore," Tomic said. "It's not there. I couldn't care less if I make a fourth-round US Open or I lose (in the) first round. To me, everything is the same. I'm going to play another 10 years, and I know after my career I won't have to work again."

Zverev broke Tomic late in the first set and again early in the second set, after which the Australian said he mentally "wasn't there." Tomic also admitted that when he called for a medical timeout, he did so to "try to break a bit of momentum" — although Zverev said later that he believed Tomic was injured.

Zverev finished with 18 aces, compared to Tomic's four. He also had 11 fewer unforced errors than Tomic, who committed 25.

Meanwhile, Arina Rodionova saved Australia's blushes — and seven match points — as she became the first Aussie through to the second round at Wimbledon on Tuesday after five previous hopefuls crashed out.

The qualifier, and world No. 166, dumped out Russian 16th seed Anastasia Pavlyuchenkova 6-3, 6-7 (6/8), 9-7 in a rollercoaster encounter, taking it on her own fifth match point. The Australian No. 4's reward for her first Wimbledon singles win is a second round clash with Han Xinyun of China or Kazakhstani wildcard Zarina Diyas.

Former top-10 player Ernests Gulbis has won a match for the first time in more than a year. And the score was about as lopsided as can be. Gulbis beat Victor Estrella Burgos 6-1, 6-1, 6-2 in less than 1½ hours to reach the second round at Wimbledon. It was the Latvian's first tour-level, main-draw victory since the 2016 French Open.

After that, he went 0-5 in such matches — until Tuesday at the All England Club. He also failed to get out of qualifying at five tournaments in that span.

The 28-year-old Gulbis once was considered an up-and-coming talent in tennis. In 2014, he reached the semifinals at Roland Garros, beating Roger Federer along the way, and got to a career-best No. 10 in the rankings.

But a series of injuries followed, and Gulbis' ranking has fallen all the way to 589th.

Tenth-seeded German Alexander Zverev booked a spot in the second round with a 6-4, 7-6(3), 6-3, win over Evgeny Donskoy of Russia. The 20-year-old's older brother Mischa also reached round two by beating Tomic in straight sets.

The Zverevs became the first pair of seeded brothers to reach the second round in the singles at Wimbledon since Gene and Sandy Mayer in 1982.

Third seed Karolina Pliskova beat Russian Evgeniya Rodina 6-1, 6-4 to reach the second round. The Czech world No. 3 will be hoping to improve her record at the championships after losing in round two on her last four appearances.

Agnieszka Radwanska overcame a tough first set before wrapping up her match in style, claiming a 7-6(3), 6-0 victory over Jelena Jankovic. And Australian Daria Gavrilova, the 20th seed, lost to Croatian qualifier Petra Martic 6-4, 2-6, 10-8 in a battle that lasted for two hours and 35 minutes on Court 14. — Agencies