Messi's Barcelona show sees off Spartak

It took another Lionel Messi show of nerve and class to rescue FC Barcelona from a shock home defeat by FC Spartak Moskva in their UEFA Champions League Group G opener.

Competition top scorer for the last four seasons, the Argentina forward's second-half double meant despair for Unai Emery's visitors. They had overcome the concession of Tello's 14th-minute effort to lead through a Daniel Alves own goal and a cool strike from midfielder Romulo just before the hour.

The victory came at a cost, however, as Gerard Piqué joined Barcelona's list of injured defenders, limping off with a bruised foot early in the first half. Initially it appeared that the centre-back's absence had not caused a blip in the Azulgrana's forward play. Moments after he departed, his face a picture of frustration, Xavi Hernández slipped the ball to his right and Tello took possession.

The young winger has been a Tito Vilanova favourite in all three competitions so far this season and showed why when he edged around Kirill Kombarov and thumped a shot into the bottom corner of the net. It was his third UEFA Champions League goal in a total of 98 minutes on the pitch since his debut last term – but not the shape of things to come here.

Momentarily it seemed that the deluge was about to commence. Spartak were unused to a team treating the ball like a personal possession and while Vilanova would have wanted more efficacy from Messi, matters looked under control. However, Emmanuel Emenike is blessed with real, raw pace and the home back four, without Carles Puyol and Éric Abidal, is not. Gradually the Nigeria forward found his range and began to pull Javier Mascherano and Alex Song, Piqué's replacement, all over the place.

Close to the half-hour mark he got his reward. Zipping past Mascherano, Emenike crossed fiercely and once the ball beat Song it was Alves who bundled it into his own net. The response was quick. Xavi's corner gave Sergio Busquets a free header, which he scorned, and when another Xavi chip let Cesc Fàbregas pull a terrific save from Andriy Dykan in the 36th minute, another goal for Barcelona appeared only a matter of time.

Yet after the break Spartak gave notice of their intent. Romulo tested Víctor Valdés following a lovely flowing move and after Aiden McGeady hit one past the post, it was 2-1. Ari and McGeady combined and the Republic of Ireland winger's pass let Romulo skip past Adriano to score.

Salvation for Barcelona took a while. Tello rounded McGeady with 18 minutes left and fed Messi for a tap-in. The draw became a win for the Blaugrana when substitute Alexis Sánchez crossed for last season's 14-goal top scorer to dart in and head past Dykan to an enormous roar.