Seattle @ Boston preview

Last Meeting ( Jul 31, 2013 ) Seattle 4, Boston 5

The Boston Red Sox need only four wins to match their total from the entire 2012 season, and one statistic is telling for the dramatic improvement this year. The Red Sox notched their major league-leading 10th walk-off victory in 15 innings against the Seattle Mariners on Wednesday to move into first place in the American League East - one-half game ahead of Tampa Bay. The Red Sox go for a three-game sweep against the Mariners on Thursday.

Seattle finished July with a 15-10 record, but it has dropped five consecutive decisions to Boston in that span. The only win over the Red Sox last month came behind ace Felix Hernandez, who will take the mound for the series finale. The 27-year-old right-hander has not lost since May 25 against Texas, posting a 6-0 record during an 11-start unbeaten streak that includes six straight outings in which he has allowed two runs or fewer.

TV: 7:10 p.m. ET, ROOT (Seattle), NESN (Boston)

PITCHING MATCHUP: Mariners RH Felix Hernandez (11-4, 2.34 ERA) vs. Red Sox RH Ryan Dempster (6-8, 4.24)

Hernandez put together a sensational string of five starts in July, going 3-0 while allowing a total of five runs. He did not factor in the decision last time out despite striking out 11 and allowing one run in nine innings against Minnesota. Hernandez beat the Red Sox in Seattle on July 8, giving up two runs in seven innings to improve to 7-2 with a 3.13 ERA in 13 career starts versus Boston.

Dempster ended a streak of four straight no-decisions by winning in Baltimore in his last start, giving up two runs over 5 1/3 innings. He has pitched more than six frames only once in his last six starts, but the Red Sox have piled up 46 runs during that span. Dempster lasted only 3 1/3 innings and was pounded for seven runs (four earned) in Seattle last month but managed to avoid the loss.

WALK-OFFS

1. Red Sox 2B Dustin Pedroia homered and drove in three runs in each of the last two games - the first time in his career he has registered back-to-back games with at least three RBIs.

2. Mariners 3B Kyle Seager batted .396 (38-for-96) in July.

3. Dempster averaged more than 8 1/2 strikeouts in five April starts, but he has not fanned more than four in eight straight outings.

PREDICTION: Mariners 5, Red Sox 2