Doug Fister was hammered in his season debut with the Washington Nationals, but he has been sensational since and will look to prevent a three-game sweep in Sunday's series finale at the St. Louis Cardinals. Fister has won five consecutive starts and will attempt to halt a three-game losing streak for Washington, which had won eight of 10 before arriving in St. Louis. The Nationals have managed one run and six hits in dropping the first two games of the series.Like Fister, Jaime Garcia got a late start to his season while recovering from shoulder surgery but is rounding into form to bolster an already-imposing pitching staff. St. Louis is 5-1 in its last six games, surrendering a total of one run in the victories. Matt Adams has made an immediate impact since returning from the 15-day disabled list, belting a homer in Friday's 1-0 win and clubbing a solo shot for the go-ahead run in Saturday's 4-1 victory.TV: 2:15 p.m. ET, MLBN, MASN2, WUSA 9 (Washington), FSN Midwest (St. Louis)PITCHING MATCHUP: Nationals RH Doug Fister (5-1, 2.68 ERA) vs. Cardinals LH Jaime Garcia (2-0, 4.26)Fister is coming off a stellar outing at San Francisco in which he scattered eight hits over seven scoreless innings to extend his winning streak to five. It also marked the sixth consecutive start in which Fister has permitted two runs or fewer, although the eight hits were his highest total allowed since his season debut. Fister has yielded only two runs in his last three road starts spanning 19 1/3 innings.Garcia is coming off a masterful performance in Toronto, where he yielded only three hits over seven scoreless innings in his fifth start of the season. The only blip in the outing for the 28-year-old Mexican was walking three batters after not issuing a free pass over his first four turns. Garcia has made five career starts against the Nationals and owns a 3-1 record and 3.29 ERA, but he is allowing them to bat a collective .295.WALK-OFFS1. Adams is 12-for-30 in his career versus Washington.2. Seldom-used LF Scott Hairston could get a start Sunday - he's 4-for-6 with a homer against Garcia.3. Cardinals CF Peter Bourjos is 4-for-8 lifetime versus Fister. PREDICTION: Cardinals 3, Nationals 2