paris saint-germain won their first trophy of the season by retaining the league cup with victory over 10-man bastia .
ibrahimovic , who missed last season 's final through injury , opened the scoring from the penalty spot after sebastien squillaci was sent off , and doubled the lead just before halftime .
thiago silva holds the french league cup aloft after psg beat bastia 4-0 in the stade de france on saturday .