It will take more than an inspired substitution for romance to bloom between Rafael Benitez and Chelsea's fans, but, on a freezing Valentine's night here, a late winner from Oscar ensured this loveless marriage of inconvenience remains intact.
The Brazilian scored within 45 seconds of being introduced as an 82nd-minute substitute by Benitez, ensuring they avoided embarrassment as well as ignominy on a Europa League debut that saw them largely sink to the occasion.
No reigning European Cup holders have ever competed in the Europa League before and Chelsea marked this unwanted slice of history with a display to match.
This is a competition they never wanted to contest but Chelsea could not claim to be out of place, looking Champions of Europe in name only on a freezing evening.
The game looked destined for a goalless draw that would have done little for fragile confidence when Oscar intervened, exchanging a one-two with the otherwise hapless Fernando Torres and sliding the ball past Tomas Vaclik in the Sparta Prague goal.
It brought relief to Benitez and the estimated 1,000 Chelsea fans who made the trip to Prague, embracing a Thursday-night schedule that could see them tour the stag party capitals of Europe, with a possible date in Amsterdam against Ajax in the last 16.
It seems a long way to come to boo the manager but that did not stop them.
Unsurprisingly there was no chorus of approval after the Oscar substitution turned the game, but the jeers are unlikely to have any effect on Benitez.
His three months at Stamford Bridge have proved beyond doubt he has a thick skin, a point he emphasised by spurning a coat on a sub-zero evening.
While he claimed not to feel the cold – "I get quite agitated on the touchline so I don't have time to feel cold" – he did admit to pleasure in the impact of his substitution.
"Normally you try to change things. (Juan) Mata was doing a great job but was a bit tired. We needed fresh legs and the quality of Oscar is pretty good because he made a difference. The idea was to keep quality on the pitch and to have fresh legs."
Benitez also maintained it was a competition worth Chelsea's full attention. "It's a competition we have to play now. It's a European competition and we must realise we have an opportunity to win a trophy. If we progress, they will see that opportunity and it will make a difference. Hopefully we can keep playing well and winning to the end."
Despite this commitment, Benitez selected an understrength team with Marko Marin and Ryan Bertrand replacing Oscar and Ashley Cole, and John Terry restored only to the bench because of a lack of match fitness.
Marin is an irregular starter but he was Chelsea's brightest player in the opening period. His movement and link-up play offering the likeliest source of a breakthrough, but he was undermined by familiar failings elsewhere.
Torres endured another night to forget, and David Luiz's absence through suspension robbed Chelsea of the midfield assurance that underpinned their 4-1 win over Wigan last weekend, leaving the back four repeatedly exposed.
Sparta Prague had not played a competitive game since December 6 but there was no evidence of rust from the winter break. After weathering a brief early flurry from Chelsea, in which Frank Lampard drew a facile save from Tomas Vaclik, the Czechs were far the more threatening side.
Had centre-forward David Lafata not proved just as ineffective as Torres, they might have made Chelsea pay. He spurned a clear opening in the 15th minute, volleying over from 10 yards after Tomas Zapotocny got in behind Bertrand to find him unmarked.
With no control in midfield Chelsea were reliant on the counter-attack and their best move of the half almost brought them a barely-deserved lead.
Fortunately for the home side the final chance, after a neat combination between Marin, Eden Hazard and the returning Mata, fell to Torres.
Presented with a clear shooting chance from around the penalty spot under minimal pressure, the Spaniard froze, toe-poking the ball weakly towards goal. Worse was to come. Midway through the second half he managed to slice a half-volleyed shot out for a throw-in.
With his sole eligible centre-forward in apparently terminal decline and immune to his attempts at revival, Benitez must despair. (© Daily Telegraph, London)