Hello
Austria won 3-2 against Holland while Lewandowski's equaliser made it 1-1 for Poland against France in Group D.
Baumgartner, Trauner and Arnautovic scored in a 3-1 win for Austria.
Poland too progressed, with a better goal difference, after Mexico best Saudi Arabia 2-1.
Robert Lewandowski's 58th minute penalty was only the second shot on target Poland had all game.
The Polish striker secured Barca's points in the 20th minute when he sped into the area, made a brilliant cut inside to clear a defender and slotted the ball to the goalkeeper's left.
Lewandowski, who came on as a substitute after the goal, continued his fine start to life in Spain with Barca's second 25 minutes from time to put the visitors in command.
The 3-0 win win over Sevilla lifts Barcelona to second place in the table on 10 points, two behind leaders Real Madrid who beat Real Betis 2-1.
The Polish striker scored his first goal in competition for Barcelona when he opened the scoring in the first minute.
Barcelona dominated the match with almost 70 per cent of possession and 18 goal attempts to two for Rayo.
Lewandowski, who scored 344 goals for Bayern in 375 appearances, joined Barcelona in a deal worth 45 million euros earlier this month, after forcing a move from the German club.