Romelu Lukaku's second-half header saved an under-par Chelsea as they began their Champions League defence with a 1-0 win over Zenit at Stamford Bridge.

Lukaku brilliantly headed home Cesar Azpilicueta's deep cross (69) for his fourth goal in four appearances back at Chelsea, in a game where the European champions struggled to create clear-cut chances.

Zenit nearly grabbed an equaliser late on as sub Artem Dzyuba failed to convert at the far post with the goal gaping, summing up a nervy and at times frustrating opening night in Group H for Thomas Tuchel's side.

With Juventus winning 3-0 at Malmo, Chelsea sit second in their group, before going to the Italian side on September 29 for matchday two. Tuchel's side remain unbeaten this season after five games in all competitions.

Player ratings

Chelsea: Mendy (7), James (6), Azpilicueta (6), Christensen (7), Rudiger (8), Alonso (6), Kovacic (7), Jorginho (6), Mount (7), Ziyech (5), Lukaku (7)

Subs: Havertz (6), Chilwell (NA), Thiago Silva (NA), Loftus-Cheek (NA)

Zenit: Kritsyuk (6), Sutormin (5), Chistiakov (5), Rakitskyy (6), Douglas Santos (5), Malcom (6), Wendel (6), Barrios (5), Kuzyaev (5), Claudinho (7), Azmoun (7)

Subs: Dzyuba (5), Erokhin (5), Kravtsov (NA), Mostovoy (NA), Krugovoy (NA)

Man of the match: Antonio Rudiger

How Lukaku showed clinical edge again in narrow win

Fireworks greeted the European champions before the game, four months after their triumph over Man City in Porto, but there was a lack of spark on the pitch for the first hour as the visitors frustrated Chelsea.

Zenit were compact and disciplined in the first half as Chelsea struggled to create any chances of note, the hosts failing to register a shot on target until the 47th minute.

Hakim Ziyech was wasteful, Lukaku wasn't being utilised and despite Mateo Kovacic's best efforts, the midfield were struggling to connect with the forward line.

The game came to life in the second half from an unlikely attacking source as defender Antonio Rudiger burst forward 70 yards from defence, taking on two Zenit players before lashing a couple of yards wide from the edge of the box, a goal that would have brought the roof off Stamford Bridge.

Rudiger was then imperious at the other end, denying Sardar Azmoun a shot on goal having been played through one-on-one with Edouard Mendy, as the German defender proved why he is now being regarded as one of the best defenders in world football.

Lukaku barely had a sniff as the game approached the final quarter, but as he showed on Saturday in the 3-0 win over Aston Villa, the Belgian only needs one opening.

Crossing from deep on the right, Azpilicueta's delivery was met by Lukaku at the far post, directing his header into the ground and beyond Stanislav Kritsyuk for his seventh goal in six games this term for club and country. Lukaku, as he so often does, turned a decent delivery into a brilliant one.

Chelsea smelled blood and looked for a second, but after several moments of pinball in the box, failed to find it, giving Zenit hope of an equaliser.

And they nearly got it as Azmoun's centre from the right found Dzyuba on the stretch a few yards out, but the substitute could only get the faintest of touches on the stretch as the ball fell wide.

Chelsea previous defence of a Champions League crown didn't go to plan - Roberto Di Matteo was sacked in November 2012 following a 3-0 defeat by Juventus that knocked the Blues out just six months after their triumph in Munich - but there's far more optimism that this side can progress with minimal fuss.
Their next game in Turin in two weeks will surely be their toughest test.

Merson: Chelsea must get used to this
Paul Merson on Soccer Special:

"Lukaku is an outstanding centre-forward. He didn't have a lot to work with, he didn't have a lot of chances, but the header was special.

"They were efficient, Chelsea, and it was hard for them. They have earned the reputation that teams will now come to Stamford Bridge, kick off and park the bus. That's what happens when you are a top team. Chelsea will face that, l would say, in every Champions League match they play until the quarter-finals."

Chelsea's remaining Champions League fixtures

September 29: Juventus (A) - kick-off 8pm

October 20: Malmo (H) - kick-off 8pm

November 2: Malmo (A) - kick-off 5.45pm

November 23: Juventus (H) - kick-off 8pm

December 8: Zenit (A) - kick-off 5.45pm

What's next?

Chelsea now go to Tottenham in the Premier League on Super Sunday, live on Sky Sports Premier League at 4.30pm, before a Carabao Cup third-round clash at home to Aston Villa on Wednesday September 22 at 7.45pm.

Their next Champions League game is at Juventus on Wednesday September 29 at 8pm. Zenit host Malmo on the same day at 5.45pm.

UEFA Press Kit

Click Here For Official Team Sheet

Teams

Chelsea Mendy, Azpilicueta (c) (Silva 83), Christensen, Rudiger, James, Kovacic, Jorginho, Alonso (Chilwell 83), Ziyech (Havertz 63), Lukaku, Mount (Loftus-Cheek 90+3)
Subs Not Used Bergstrom, Kepa, Chalobah, Sarr, Barkley, Saul, Hudson-Odoi, Werner
Booked Azpilicueta
Goals Lukaku 69

Zenit St Petersburg Kritsyuk, Sutormin, Chistiakov, Rakitsky Krugovoi 88), Santos (c), Malcom (Dzyuba 75), Wendel (Yerokhin 75), Barrios, Kuzyaev (Kravstov 82), Claudinho Mostovoy 88), Azmoun
Subs Not Used Kerzhakov, Odoevski, Khotulev
Booked Rakitsky
Goals

Attendance 39,525

Referee Bartosz Frankowski (POL)

VAR Marco Fritz (GER)