Arsenal closed in on qualification for the knockout stages of the Champions League with a 3-1 win over Olympiacos at Emirates Stadium.
The Gunners responded from the disappointment of defeat by Barclays Premier League leaders Chelsea as goals in each half from Gervinho and Lukas Podolski and a well-taken late strike from substitute Aaron Ramsey made it successive victories in Group B.
Another three points against Schalke, who drew at home to Montpellier, here in a fortnight's time would all but seal progress and probable seeding for the last 16.
With manager Arsene Wenger watching in the stands for the second of his three-game European ban, the Gunners started brightly as the rain lashed down on north London. In the 11th minute, goalkeeper Balazs Megyeri tipped over Santi Cazorla's curling free-kick. Olympiacos showed some intent, if without really stretching the Arsenal rearguard.
Arsenal keeper Mannone had not had much to do in the first half hour, but was alert enough when Ricardo Paulo Machado's cutback was turned goalwards across the wet surface by Kostas Mitroglou and the Italian got down to grab the ball as it headed towards the bottom right corner.
Olympiacos should have been in front in the 34th minute when captain Giannis Maniatis skipped down the right and crossed through the six-yard box, but arriving at pace Machado could only scoop the ball high over the crossbar.
Against the run of play, the Gunners were ahead three minutes before half-time. Kieran Gibbs and Podolski worked space down the left, and the ball was played back across the edge of the penalty area. Mikel Arteta won a 50/50 with Pablo Contreras, which saw possession break to Gervinho, who sidestepped his marker before beating the wrong-footed Megyeri with a low shot.
However, the lead did not last to the interval. Arsenal were again caught cold at the back as Italian Leandro Greco whipped over a superb cross from the left touchline, which was guided into the net by a deft header from Mitroglou, who got between the two centre-halves.
There was more urgency about the Gunners after the break. Cazorla's fired wide after good work from Gervinho, before home pressure was rewarded in the 56th minute. Again Gervinho was involved as he battled into the left side of the penalty area and picked out Podolski, who turned to drill the ball through the keeper's legs.
Theo Walcott was sent on to give the Greeks something else to worry about for the final 20 minutes, replacing Alex Oxlade-Chamberlain. Ramsey wrapped up the victory when he latched onto Olivier Giroud's flicked header from Mannone's long goal-kick to skip into the penalty area and calmly chip the keeper.