Since opening the year 1-4 with an inflated 8.01 earned run average, Vazquez has won four of his last five decisions and has allowed just three runs in his last four victories to get his ERA down to 5.62.
Vazquez was brilliant against the Toronto Blue Jays on Sunday, as he surrendered just a two-run home run to Vernon Wells in seven innings to even his mark at 5-5 on the year.
The right-hander has faced the Astros 13 times and is 3-5 against them with a 4.41 ERA.
If Vazquez is going to continue his roll he will have to do so without three- time AL MVP Alex Rodriguez in the lineup, as the third baseman is expected to miss this series because of right hip tendinitis. The Yanks did not skip a beat without the superstar on Friday, however, as Francisco Cervelli hit a two-run single in the first inning to help back a strong start from Andy Pettitte in a 4-3 Yanks win.
Pettitte (8-1) joined Whitey Ford (236) and Red Ruffing (231) as the only pitchers to win 200 games with the Yankees, surrendering three runs (two earned) in 7 1/3 innings to get the victory.
"It's special. There's not a lot of guys that have won that many games as a Yankee," Pettitte said. "So it's a good thing."
Pettitte got into trouble in the eighth inning before Joba Chamberlain got the final two outs, while Mariano Rivera worked a 1-2-3 ninth for his 15th save.
New York has now won nine of its last 12 and is one game back of the Tampa Bay Rays in the AL East.
Brett Myers (4-4) allowed four runs in seven innings to take the loss. Tommy Manzella went 2-for-3 with a two-run double for the Astros, who had won three in a row.
"To be able to go as deep as he did and to respond after that first inning to do what he did was exactly what we needed and a great job," Astros manager Brad Mills said of Myers.
Houston will pin its hopes today on righty Wandy Rodriguez, who is 3-8 with a 4.95 ERA. A 14-game winner a year ago, Rodriguez fell for the fourth time in five starts on Monday in Colorado, as he gave up three runs and nine hits in seven innings.
Rodriguez lost his only other start to the Yanks back in 2008.
New York swept the Astros in a three-game set in Houston in 2008 and is 6-1 all-time against them.