Martin shot a two-run single up the middle to cut the lead to 4-2 and break an 0-for-18 drought, and the Rangers scored twice against the bullpen in the eighth to tie the game.
"That was honestly pretty pitiful the way I executed pitches there in the seventh," Keuchel said. "I think [plate umpire] Laz [Diaz] was kind of squeezing me, but I got to make better pitches than that. The bullpen wasn't really expecting to pitch and it all fell on me there in the seventh. It kind of shored things up and I was able to get out of it with two runs, but I wasn't making very good pitches. It could've been a lot worse than it was, so I'll take the positive on that note."
After Tony Sipp retired Martin to end the 10th on George Springer's game-saving catch in right field, the Astros' bullpen was relentless. Sam Deduno recorded two quick outs to start bottom of the 14th -- Hank Conger had given the Astros' a 6-4 lead with a two-run homer in the top of the inning -- and eventually the reliever retired Roughned Odor to strand the bases loaded for his first career save.
Pat Neshek and Joe Thatcher gave up runs in the eighth to tie the game and Chad Qualls was credited with a blown save, but Sipp, Luke Gregerson, Will Harris and Deduno combined to hold the Rangers to two hits in six scoreless innings.
"We used them in some funky orders," Astros manager A.J. Hinch said. "We called down and they were ready. There were different situations for each of them. For one of the first times you could say every one of them contributed in some way. We needed every ounce of pitching we had today."
Harris, who got the win, threw two innings for the second day in a row. He struck out the side in the 12th before throwing a perfect 13th.
"Guys are trying to go out there and do their job every time," Harris said. "Nobody wants to give up hits or runs or walks or anything like that. So it's just good to get a win in games like that. You know it can really be deflating to play that long and be so close and end up losing. So, it just is uplifting to come out with a 'W' for sure."
Hinch used his closer, Gregerson, in the 11th to retire Elvis Andrus, Adrian Beltre and Prince Fielder instead of saving him for a possible lead later.
"The game was going pretty smooth on our end and Dallas was pitching his butt off before we ran into a snag with back-to-back two-run innings," Gregerson said. "Guys stepped up and battled and pitched hard and located well and got guys out."
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.