A walk-off home run for Jose Altuve and a three-game sweep Thursday night, with a shiny new starting pitcher taking the hill a day later in Scott Kazmir. Craig Biggio’s Hall of Fame ceremony looms on the weekend. Even the first-place Angels cooperated Thursday with a loss. There’s been plenty to enjoy all year, but these few days are as close to a midseason zenith as an Astros fan will find. Jose Altuve’s fourth hit of the night just barely crept over the yellow line along the Crawford Boxes, good for the first walk-off homer of the superb second baseman’s career and a ninth-inning tie-breaker at Minute Maid Park in a 5-4 win over the Red Sox. The Astros have won five of six games since the All-Star break. Altuve’s teammates and an orange cooler filled with a blue sports drink waited for him at home plate. A little more than a minute later, the three-game sweep was secured after the the umpires made sure the ball was indeed gone with a review. “It’s good news with Kazmir, one of the best pitchers in the league, now he’s going to be part of us, he’s going to throw tomorrow,” said Altuve, whose one-out homer came off lefty Craig Breslow. “Big shot to win a game if he’s pitching. “We were going back and forth today but all that matters at the end of the day is getting the win. This team is going to be able to do this, come back and swing the bat today good.” The game had been tied since the top of the eighth inning, a frame that left open a possible blame game for the Astros that no one cared too much about once Altuve made it all better. “Anytime you have a walk-off win at home all mistakes are forgiven,” manager A.J. Hinch said. With the Astros ahead 4-3 with two out and a runner on second, manager Hinch pulled Will Harris in favor of Luke Gregerson with No. 8 hitter Mike Napoli coming to the plate. Napoli had already homered in the game. Harris, typically very effective, had already thrown 22 pitches and had allowed a home run in the inning, to David Ortiz. Hinch thought Harris was taxed. First base was also open with No. 9 hitter Ryan Hanigan to follow, but he didn’t want to walk Napoli and take away the open base. Gregerson gave up an atom ball to Napoli that Preston Tucker misjudged in left field — a tough play, but one that needed to be made — bringing Hanley Ramirez home to tie at 4. “It’s tough but you know I’m a professional baseball player, I should catch it obviously,” Tucker said. “What sucks the most is that it’s an earned run on the pitcher, it’s not an error on me.” No one had scored since the Sox pulled ahead 2-1 in the second inning before the Astros scored three times in the seventh for a 4-2 lead. Sox righty Alexi Ogando’s full-count fastball was 95 mph on the inner half to pinch-hitter Colby Rasmus, who nonetheless turned on it for his 13th homer, a screamer to right with one out. That tied it at 2. Altuve’s third hit of the night, a single, brought Marwin Gonzalez to the plate to face a new pitcher, Junichi Tazawa. Gonzalez, who hit a solo homer in the first inning, rope a double to center but was thrown out trying to stretch a triple with a headfirst dive. The hits kept coming with two down: Carlos Correa doubled and Evan Gattis singled the shortstop home for a 4-2 lead, a needed extra run. Harris, typically infallible, gave up a leadoff homer to Ortiz in the top of the eighth, cutting the lead to 4-3. Ramirez’s single and stolen base — which took a 4-minute, 19-second, review initiated by the umpires to uphold a safe call — put the tying run in scoring position with none out. Harris struck out Pablo Sandoval swinging and got Alejandro De Aza to sky a pop up to short in a long at-bat for two straight outs, bringing Napoli to the plate.