RIO DE JANEIRO, Sept 20 (Reuters) - Colombian striker Miguel Borja scored on the stroke of halftime to give Gremio a surprise 1-0 win way at Flamengo on Sunday and hand the Rio de Janeiro club their first league defeat in five matches. Borja rose between two Flamengo defenders to head home a cross from the left in first-half stoppage time to give the Porto Alegre club all three points. Borja had a chance to score a second in the 98th minute but his penalty was saved by Flamengo keeper Diego Alves. It was Flamengo"s first defeat in nine games and came days after they knocked Gremio out the Copa do Brasil 6-0 on aggregate. The points lifted Gremio a place to 17th but they still ended the day in the relegation zone. Flamengo are third, 11 points behind leaders Atletico Mineiro but with two games in hand.