Kadeisha Buchanan in walking boot for Chelsea loss to Barcelona in Champions League semi

An early goal by Caroline Graham Hansen gave Barcelona a 1-0 win at Chelsea in the first leg of their Women's Champions League semifinal on Saturday in London, England.

Graham Hansen put Barcelona ahead just four minutes into the match at Stamford Bridge when the Norway forward cut in from the right and drilled a long-range shot into the top corner.

Substitute Marta Torrejon almost grabbed a second goal for the visitors when she headed off the post in the 82nd.

The other semifinal starts on Sunday when Arsenal is at Wolfsburg.

Chelsea centre back Kadeisha Buchanan of Toronto was spotted on the sideline in a walking boot. She was injured recently and also didn't play a week ago in an FA Cup semifinal against Aston Villa.

Buchanan, 27, also sat out a friendly for Canada two weeks ago with No. 5 France in Le Mans. 

Fellow Canadian Jessie Fleming appeared in Saturday's game as a substitute in the 84th minute. She signed a new contract with Chelsea in November that will keep the midfielder at the English club until the summer of 2025.

Fleming has won 109 caps for Canada and captained her country. She made her senior debut at 15, becoming the second-youngest player to ever play for Canada.

Fleming was part of Canada's Olympic champion team in Tokyo and won bronze at the 2016 Games in Rio. In 2021, she was honoured as Canada Soccer player of the year.

Chelsea rarely threatened on attack

Saturday's game was a rematch of the 2021 European final, when Barcelona routed Chelsea 4-0 to its first continental title. Graham Hansen scored the fourth and final goal for Barcelona two years ago.

Her goal in the opening stage gave Barcelona 36 goals in the competition this season, more than the other three semifinals.

But instead of falling apart in the first half like in 2021, when Barcelona netted all four of its goals within the first 40 minutes, Chelsea held firm in defence despite never mounting much of a threat in attack.

With Barcelona apparently content to sit on its lead with the return leg at home, Chelsea only came close to equalizing on the half-hour mark. Barcelona needed defender Lucy Bronze to block a goal-bound shot by Guro Reiten after she was played through by Sam Kerr and rounded goalkeeper Sandra Panos.

Barcelona upped the pressure after halftime, though, and top playmaker Aitana Bonmati got more involved with touches in the midfield. After that, Chelsea rarely had the ball in Barcelona's half and is fortunate to still be in the tie.

Chelsea reached the final four after surprising titleholder Lyon in a penalty shootout in the quarterfinals. It will now need to pull off another upset on Thursday at Camp Nou.

Barcelona entered the tie on a run of 60 consecutive Spanish league wins, including all 25 games this season -- its last domestic loss was in July 2021 -- even though it can't count on two-time Ballon d'Or winner Alexia Putellas.

The midfielder has returned to team training after tearing her ACL last July. But she was not on the squad for Saturday's game. After the final whistle, she congratulated her teammates for the victory that gives them a strong chance of returning to the final for a third straight year.

Torrejon had to replace Bronze, an England player, for an apparent leg injury midway through the second half.