AC Milan snatched a late 3-1 win over Celtic at the San Siro, Inter Milan beat Anderlecht by the same score in Belgium and Barcelona trounced Shakhtar Donetsk 3-0 as the night's action went largely according to form.

Late goals steered Werder Bremen to a 2-1 home victory over 10-man Valencia and PSV Eindhoven to a 1-0 win over Panathinaikos, but there was only frustration for England's champions as Arsenal were held 1-1 at Rosenborg Trondheim.

CSKA Moscow recorded their first ever Champions League win by beating ailing Paris St Germain 2-0 on another entertaining night that added 23 goals to Tuesday's 31-goal bonanza.

Several teams will be returning home believing they have one foot in the knockout phase while others, such as Porto, will know they are already in deep trouble.

Chelsea fit comfortably into the former category after following up their 3-0 win over PSG a fortnight ago with a convincing victory at Stamford Bridge to lead Group H on six points.

The meeting between Mourinho and the club he guided to consecutive UEFA Cup and Champions League trophies, along with two Portuguese league titles, had been one of the competition's showcases since the draw was held last month.

Alexei Smertin gave Chelsea an early lead, Didier Drogba added a second after the break and John Terry put the game out of reach after Benni McCarthy had pulled one back for Porto, much-changed since Mourinho's close-season departure.

The Portuguese champions, held to a goalless draw by CSKA a fortnight ago, have garnered only point in the defense of their title and trail the Russians by three.

Group F is also taking shape with Barcelona and Milan both racking up six points while Shakhtar and Celtic have yet to get a point on the board.

Though Shakhtar were never in with a chance against Barca, who scored through Deco, Ronaldinho and Samuel Eto'o, Celtic suffered a second European heartbreak in as many weeks.

On the verge of registering their first away point in the Champions League at 1-1, Celtic were floored by an 89th minute strike by Filippo Inzaghi and a stoppage-time goal by Andrea Pirlo.

It was all too familiar for Celtic fans, whose team were drawing 1-1 with Barcelona a fortnight ago with 12 minutes left only to lose 3-1.

Inter's second consecutive win, courtesy of goals from Obafemi Martins, Adriano and Dejan Stankovic, secured them a three-point lead over both Werder Bremen and Valencia in a wide-open Group G.