Marcos Alonso's late header helped Chelsea to a hard-fought 1-0 win away to Slavia Prague in their Europa League quarterfinal first leg on Thursday.
Chelsea boss Maurizio Sarri made seven changes to his last XI but fielded a strong team in Prague, leaving an in-form Eden Hazard on the bench after his outstanding two-goal outing on Monday as the Blues beat West Ham to move into third place in the Premier League.
However, the visitors found chances hard to come by over the course of the first 45 minutes as the league leaders in the Czech top flight dug in with a raucous home crowd urging them on in a scoreless first half.
Despite a lack of goals, the second half provided some entertaining end-to-end football, with Slavia Prague's Ibrahima Traore stinging Kepa Arrizabalaga's palms from distance on 70 minutes and Chelsea seeing a goal ruled out for offside shortly after.
Alonso's header from an inswinging Willian cross as full-time approached wound up being the difference for Chelsea, who return home for the second leg on April 18 with an important away goal giving them the upper leg for passage to the semifinals.
"I'm very happy with the result and also with the performance, because at this moment we are able to suffer, in the past we were not," Chelsea manager Maurizio Sarri told reporters.
"In the past, when we were in trouble, we conceded immediately a goal, now we did not concede anything."
Asked about his lineup, Sarri weighed in on his decisions to start with Hazard and Callum Hudson-Odoi on the bench.
"Oh, I don't know [about Hudson-Odoi on Sunday]," said Sarri. "But in my opinion he needed to rest. And so, in this match, he was out. Emerson [Palmieri] was also out. But of course he is in my mind for the next match, but I have to see the last two trainings.
"No, at the beginning of the match I wanted [Hazard] on the bench because I thought that, probably, the match was really very difficult. Probably I'd need to use him. Of course, if at the end of the first half we were 1-0, I wouldn't have used him."