PORTO ALEGRE, Brazil, Jan 28 (Reuters) - Flamengo fought back from a goal down to win 4-2 at Gremio on Thursday and maintain their hopes of winning a second consecutive league title in Brazil.Diego Souza had put the home side ahead with his 10th league goal of the season five minutes before halftime but three goals in nine minutes early in the second half put Flamengo in control.Everton Ribeiro made it 1-1, Gabriel Barbosa put the visitors ahead with a sumptuous strike from 20 metres before Giorgian De Arrascaeta made it 3-1.Souza scored a second for Gremio after 85 minutes to give the hosts a flicker of hope but Mauricio Isla restored Flamengo’s two-goal lead in stoppage time.The win lifts Flamengo to second in the Serie A table, four points behind Internacional with six games to play.Gremio are sixth, 11 points off the lead. (Reporting by Andrew Downie; Editing by Peter Rutherford )