Nicolas Anelka's first European goal since November divided the sides in a game whose balanced shifted after the goal.

For Chelsea it was a familiar story of domination without penetration at home before the goal came just after half-time. But then instead of the push for a second, the Portuguese side increasingly took control and it took a series of Petr Cech saves to keep them at bay, although only one was a proper test of the Chelsea keeper.

At the other end, Helton in the Porto goal pulled off an outstanding save from Salomon Kalou to deny the Blues that elusive second goal.

On a very wet night it was Anelka who attempted to capitalise on an early mistake from Pereira, his cross not finding a colleague, and then Lampard forced a sprawling save from Helton with a typical long-range dipping shot.

At the other end, Hulk, sporting the biggest backside seen inside Stamford Bridge since Jimmy Floyd Hasselbaink, launched a Jimmy-like shot which in the teeming rain, Cech opted to save with his legs.

From the corner that followed, Rodriguez headed close but over as he was challenged by Essien.

Lampard then guided a header down but at the keeper from an Ivanovic cross. It was an all-action opening six minutes.

Two minutes later there was a collision between the two captains, more specifically between Terry's head and Bruno Alves's elbow as both jumped. Benefit of the doubt marks it down as an accident but a jarred JT still needed prolonged treatment.

Less time on the turf was spent by Hulk after he was caught by a tackle on halfway from Essien, but the challenge still warranted the game's first yellow card according to the Austrian ref.

Malouda followed into the book soon after as he attempted to retrieve an attack outside the Porto box. Between those two cards Anelka had seen an on-target shot blocked by a defender.

Chelsea began to work spaces behind the full-backs. From such a position Lampard fed Anelka but the shot was tame. Then Lampard headed wide from a Malouda cross before firing at the keeper on 26 minutes after Kalou's pass. The flag was up, although replays suggested incorrectly.

Both Ballack, and Kalou, the latter playing behind Anelka and alongside Malouda in a 4-3-2-1 shape, were inches away from converting a well-flighted Ivanovic cross on the half-hour. The Serb was right-back in place of suspended Bosingwa.

Porto had left out several fresh signings for this season, including striker Falcao. One theory was that Jesualdo Ferreira had selected his tallest side. He had certainly told his players to play on the counter-attack.

Approaching half time they enjoyed their best spell yet as Chelsea began to pass loosely on an increasingly sodden surface. Midfielder Gaurin headed narrowly over as the Blues defence was caught out of position.

Malouda shot over at the other end as the Blues attempted to press again but in stoppage time Porto midfielder Raul Meireles escaped into space, only to head straight at Cech.

It was actually Porto who attacked first after the break but they squeezed that in during the two-minute gap between the restart and Anelka opening the scoring.

His was a lovely finish - eventually - floating the ball in from a tighter angle than his initial shot which was saved by Helton. That came after Kalou had won a challenge on the edge of the area and poked the ball through.

On 53 minutes Malouda met a Cole cross powerfully at the far post but headed into the sidenetting.

Now Porto did introduce Falcao - to play down the middle with Hulk moving wide. Before any of them touched the ball again, Fucile was lucky to escape punishment for a lunge that Malouda was nimble to escape.

On 58 minutes Ivanovic sent over a good cross, not for the only time in the game, and it took a brilliant save to keep out Kalou's emphatic header. The fact the Ivorian didn't keep it lower was the only possible criticism.

Falcao had a chance after some messy defending on 68 minutes but fired at Cech. Guarin hit a better attempt from further out, his side's fourth on-target, but again it was straight at the Chelsea stopper. The same Porto player soon after angled in a drive against Cech's shins.

The insurance of the second goal was becoming a pressing need.

Belletti was introduced for Kalou with just under quarter-of-an-hour to go but still the Porto attacks came - Hulk bulging the sidenetting.

Then it took a one-handed save from Cech from Varela's volley to preserve the lead. That was the closest the Portuguese champions had come.

Their head of steam continued into stoppage time as their European pedigree was clear to see. Chelsea survived a ball across the six-yard box before Fernando was dismissed in stoppage time for a second yellow after catching Cole late.

The final whistle was greeted with relieved cheers. Chelsea have enjoyed easier opening group stage wins than this but top the group thanks to APOEL's goalless draw in Madrid.

He was not called upon on the night but Joe Cole was on the bench for this game, his first selection since January. Eighteen-year-old striker Fabio Borini and 17-year-old defender Jeffery Bruma were also unused subs.

Chelsea (4-3-2-1): Cech; Ivanovic, Carvalho, Terry (c), A Cole; Ballack, Essien, Malouda; Kalou (Belletti 76), Lampard; Anelka.
Scorer Anelka 47.
Booked Essien 14, Malouda 17.

Porto (4-3-3): Helton; Fucile, Rolando, Bruno Alves (c), Pereira; Gaurin, Fernando, Raul Meireles; Mariano Gonzalez (Falcao 53), Hulk, Rodriguez (Varela 64).
Booked Fernando 77
Sent-off Fernando 90+1

See the full match live from midnight on Chelsea TV.