Bouchard was only 20, Halep 22. Bouchard won that matchup to reach a Grand Slam final in the sixth major tournament of her career, a month after Halep was the runner-up at the French Open.
Back at the All England Club on Tuesday, both women lost in the first round to opponents ranked outside the top 100. For Bouchard, also a semifinalist at the Australian Open and French Open in 2014, it was the latest setback in a season full of them, including 12 losses in her past 14 matches.
"It's been a huge learning process to have great results and then have, you know, so much attention, then have bad results. Just learning about the ups and downs of life and tennis, how things won't always go perfectly, like I expect them to," said Bouchard, who added that a torn abdominal muscle limited her practice time leading into the match.
"I'm always trying to keep the belief and stay true to myself and do what I need to do to become as good as I know I can be. So it's really just been kind of eye-opening, a learning experience," she added, resting her chin on her right hand, then added with a laugh: "But I'm good for the learning experience to be over now."
Her 7-6 (3), 6-4 exit against 117th-ranked qualifier Duan Ying-Ying of China made the 12th-seeded Bouchard the first Wimbledon finalist to lose her opening match at the grass-court Grand Slam tournament the following year since Steffi Graf in 1994.
Against Duan, Bouchard double-faulted 10 times and said her muscle problem, which was taped Tuesday, didn't so much affect her strokes as prevent her from preparing properly. She pulled out of a tuneup tournament at Eastbourne last week because of the injury.
"Probably wouldn't have been smart to play here, but I couldn't pass on Wimbledon," said Bouchard, the only Canadian to reach a Grand Slam singles final. "In my head, it was no question I was going to play, even though I was advised not to. It's just the way I am. It's so hard to be forced not to play tennis, especially at Wimbledon."
Duan lost all four previous matches she'd played at majors, has never been past the quarterfinals at any tour-level event and never before defeated anyone ranked higher than 75th.
"I didn't know who she was," said Bouchard, who went 19-4 in Slam matches last year but is now 4-3 in 2015 and will fall out of the top 20 in the rankings after Wimbledon.
Bouchard began working this season with coach Sam Sumyk after splitting with Nick Saviano and was asked whether she's considered making changes to her team.
"Maybe I should," Bouchard replied with a chuckle. "We've definitely not started well at all. But I believe in him and he believes in me. As of right now, it's still the plan. But there definitely has to be some improvement, some changes, because I expect to do a little better than this."
Meanwhile, the No. 3-seeded Halep was treated by a trainer for a lost toenail late in the first set of what would become a 5-7, 6-4, 6-3 defeat against 106th-ranked Jana Cepelova of Slovakia.
"I knew it would be a difficult tournament for me," Halep said, explaining that her confidence was low because of poor recent results. "But I didn't expect to lose in [the] first round."
Highly seeded players rarely do anticipate that sort of quick departure, of course.
Petra Kvitova, who beat Bouchard for the 2014 title, won 28 of 29 points on her serve -- a double-fault in the final game was the lone blemish -- in a 6-1, 6-0 victory over Kiki Bertens that required all of 35 minutes.
The second-seeded Kvitova, who is from the Czech Republic, said her parents made the trip for her first-round match, but will be heading home right away.
"I have to say 'Sorry' to them" for such a short match Tuesday, Kvitova joked.
In keeping with Wimbledon tradition, Kvitova had the honor of playing the first Centre Court match on the second day as the reigning champion.
"It was a great feeling," said the second-seeded Czech, who also won the title in 2011. "I have so many nice memories. I was very nervous before my match. The atmosphere was unbelievable, so for me it was really nice to back. I'm really glad how I played as well."
It was a performance of total dominance by the powerful lefthander. Kvitova came into Wimbledon without any grass-court matches this year after withdrawing from last week's tournament in Eastbourne with a virus.
She showed no signs of illness Tuesday as she used her big serve and flat forehand to dictate play. The 108th-ranked Bertens, who has never beaten a top-10 player, was continuously on the defensive and could not cope with the heavy pace.
In addition to her dominance on serve, Kvitova won all 10 of the points in which she came to the net. She had only three unforced errors, to go with her nine winners.
Kerber said the scoreline of the 44-minute match was misleading.
"I think it was a good match for me," she said. "Carina was playing not bad, actually. So the games [were] not like 40-0. It was very close, actually."
The Associated Press contributed to this report.