Chelsea humble Porto to qualify for Champions League round of 16

Chelsea finally had something to celebrate in their unexpectedly poor season on Wednesday after qualifying for the Champions League knockout phase with a 2-0 victory over Porto.

Chelsea not only avoided the embarrassment of dropping into the Europa League, but Jose Mourinho's team advanced as Group G winners while his former club, Porto, finished third behind Dynamo Kiev to qualify for the second-tier competition.

Fortune favored Chelsea in the 12th minute at Stamford Bridge when Ivan Marcano scored an own goal and Willian rifled a second strike past goalkeeper Iker Casillas early in the second half.

Chelsea's assured performance — albeit against largely ineffective Portuguese visitors — has been lacking so often in a season when the Premier League title defense has seen the club lose eight out of 15 games.

It was only Chelsea's ninth win in 23 matches in all competitions this season, excluding the curtain-raising Community Shield which set the tone for the campaign by losing to Arsenal.

Mourinho's decision to restore Costa to the starting lineup was rewarded early on.

It was the Spain striker's shot from Eden Hazard's through ball that was blocked by Casillas and then cannoned off Marcano into his own net. It initially appeared that Maicon had successfully cleared the ball as he scrambled back but the additional assistant referee eventually ruled it had crossed the line.

But the darker side of Costa was soon evident when he cynically stuck a leg out to trip Casillas and he was booked.

Rather than Chelsea killing off the game, Costa didn't come close to scoring again until the stroke of halftime when he sliced the ball across the face of goal.

The attacking intent required to steady nerves was evident early on in the second half. A stinging shot from Willian went straight at Casillas. When it came to Willian's next shot — again set up by Costa — there was more power and it flew into the net.

Stamford Bridge hasn't had much to cheer this season and owner Roman Abramovich seized the moment. Fist clenched in relief, the Russian billionaire smiled broadly as he celebrated in an executive box.

Now Abramovich just needs Mourinho to arrest Chelsea's Premier League slump. Otherwise the only way Chelsea will be back in the Champions League next season is by winning it for only the second time.