By Graham Wood
ATHENS, Nov 5 (Reuters) - A first-half header from Kostas Manolas and an inspired performance by goalkeeper Roberto lifted Olympiakos Piraeus to a 1-0 win over Benfica in a tight Champions League Group C match on Tuesday.
The Greek champions rode their luck against their Portuguese opponents after taking a 13th-minute lead against the run of play, but despite enjoying plenty of possession, Benfica could not find a way past Roberto who made several crucial saves.
Oympiakos moved up to second in the group on seven points, three clear of Benfica in third and three behind leaders Paris St Germain.
Despite their recent run of good form at home and in Europe, Olympiakos looked nervy in the opening exchanges and it was the visitors looked more fluid.
They could have been two goals ahead in the first eight minutes but for the reflexes of Roberto.
The Spaniard first denied Oscar Cardozo with a diving save before scampering off his line to block Lazar Markovic's goal-bound effort.
Benfica's promising start was ruined after 13 minutes, however, when Greece defender Manolas rose unchallenged to power home a header from Jose Holebas's inch-perfect set-piece.
The goal did not deter the visitors, who continued to enjoy the lion's share of possession, but Luisao's header which flashed over the crossbar from a corner was their only attacking threat heading into halftime.
The second half began in the same fashion as the first, with Benfica on top and Roberto keeping the lead intact.
The Spanish keeper produced a brilliant save to deny Markovic, blocking the Benfica man's acrobatic volley with his legs when a goal looked certain.
Saviola was replaced at halftime by Alejandro Dominquez as Michel looked to improve the supply line to lone striker Mitroglou.
But it was Roberto who continued to play a starring role for the home side, denying Benfica left-back Sílvio with yet another a fine save when he was put clean through on goal.#
There was still time for more heroics from Roberto when he palmed away a snapshot from Benfica substitute Filip Djuricic with 12 minutes left. (Editing by Ed Osmond)