There is still no guarantee that Chelsea will be able to finish the season, the reality of their precarious situation meaning even the unlikeliest of scenarios coming to pass cannot be ruled out, but by the same token there is every chance that they could yet end it by holding on to their European crown. Stranger things have happened and there will always be hope as long as Chelsea have Thomas Tuchel on the touchline, working out how to bend games in their favour. The German’s side are through to the last eight of the Champions League and Tuchel, whose moral leadership has been so impressive ever since it became clear that Roman Abramovich’s ownership could not continue, will feel the holders have a chance of lifting this trophy again after goals from Christian Pulisic and César Azpilicueta helped them see off a spirited, creative challenge from Lille. After the rows over ticket allocations and the negotiations over travel allowances, how Chelsea must have craved a quiet night. From Tuchel’s perspective there was no need for any drama. Every day has seemed to bring a new form of uncertainty for Chelsea, who felt public sympathy slipping away when they tried to get Saturday’s FA Cup quarter-final against Middlesbrough moved behind closed doors, and Tuchel’s selection suggested that he was not worried about putting on a show, the sight of eight defensive players behind Kai Havertz and Pulisic a clear indication that the visitors were focused on containment over entertainment. It certainly looked like an imposing challenge for Lille, who had created little when they lost the first leg 2-0 last month. The Stade Pierre-Mauroy was a noisy place at kick-off, the home crowd urging their players on, but in truth it was difficult to see how Jocelyn Gourvennec’s side hoped to break Chelsea down at first. N’Golo Kanté, Jorginho, Mateo Kovacic were efficient shields in front of Chelsea’s back five and there was a lack of conviction to Lille when half-chances did arrive, their initial threat broadly limited to a couple of hopeful sighters from long range from Burak Yilmaz. As the half wore on, though, there was a sense of Chelsea’s caution inviting trouble. There were a couple of nice flicks from Havertz, a zigzagging run through the middle from Kovacic, but there was little flow. Havertz and Pulisic were isolated, with Azpilicueta and Marcos Alonso under instructions not to push forward on the flanks, and Chelsea would run into difficulties after they lost Andreas Christensen, the loss of the Danish centre-back briefly causing them to lose composure at the back. Trevoh Chalobah was the player sent on in Christensen’s place and within a minute of coming on the young defender was being turned by Jonathan David. Players wriggling beyond Chalobah seems to be a weakness in his game – he was fortunate not to concede a penalty for something similar against Newcastle – and Chelsea were under pressure when he conceded a free-kick after dragging David down. The free-kick came in, the ball was not cleared and Lille screamed for a penalty when Jorginho handled as he tried to challenge Xeka. It was a blatant handball and although Davide Massa missed it in real time, there was no doubt that the Italian referee would point to the spot after being told to check the pitchside monitor, allowing Yilmaz to give Lille hope by burying a ruthless spot-kick beyond Édouard Mendy. With the home fans bouncing, it seemed that Chelsea were on the ropes. That, though, was the cue for them to show their class. Just before half-time they equalised in splendid fashion, Jorginho relishing the chance to make up for his part in Lille’s goal. The pass from the Italian was beautiful, bent with the outside of his right foot, Lille’s defence cut to shreds, and there was Pulisic running in unnoticed from the right before clipping a low shot across Léo Jardim and into the far corner. It was a vital intervention from Pulisic, a player in decent goalscoring form of late, though Tuchel was not entirely satisfied. Chelsea were still only playing in bursts and Tuchel used the interval to tweak his formation, the introduction of Mason Mount for Kovacic intended to give Lille more to worry about at the back. Yet it was Lille who carried the greater threat at the start of the second half. They almost led again when Jonathan Bamba, twisting past Alonso on the right, crossed for Yilmaz to head inches wide with Mendy beaten. There were still too many gaps in Chelsea’s defence, even with Thiago Silva at the heart of it, and they had another escape just after the hour, Xeka’s free header bouncing off the woodwork and to safety. Lille, sixth in Ligue 1, would regret those misses. With 19 minutes left the tie was out of reach, Mount darting down the left and swung a dangerous cross to the far post. Timothy Weah was not quick enough off the mark and Azpilicueta charged, kneeing the ball past Jardim to give Chelsea a fleeting sense of control over their own destiny.