Both games went in favor of Keuchel and the Houston Astros.
The next matchup will occur Wednesday in Game 5 of the American League Championship Series at Yankee Stadium, where one team will move within a game of clinching a berth in the World Series.
The series is tied 2-2 after New York rallied for a 6-4 victory in Game 4 on Tuesday. Aaron Judge homered off Lance McCullers Jr. before New York scored four runs in the eighth. Judge's double tied the score, and Gary Sanchez's two-run double off Houston closer Ken Giles gave New York the lead.
"This is a great series," Houston manager A.J. Hinch said. "This is two really good teams fighting for the chance to represent the American League. I don't think anyone thought the series was over two games ago."
The first postseason meeting between Tanaka and Keuchel occurred in the 2015 AL wild-card game in New York. In Houston's 3-0 victory, Keuchel struck out seven and allowed three hits in six innings while Tanaka allowed two runs on four hits in five innings.
The second playoff meeting occurred in the ALCS opener on Friday in Houston. Keuchel allowed four hits in seven scoreless innings while striking out 10. Tanaka gave up two runs on four hits in six innings during the Astros' 2-1 victory.
"He's a very good pitcher," Keuchel said of Tanaka. "And if it weren't for some extraordinary performances, we'd be singing his praises multiple times.
"When I've pitched against him in the regular season and in the postseason, it's a feeling that you have to be on top of your game because there's not going to be a lot of runs produced from our part. That brings a challenge."
In Game 1, Keuchel threw one changeup. In the 2015 wild-card game, he threw the pitch five times. During the regular season, he threw it 13 percent of the time. He threw just seven changeups May 11 in a start at New York.
"It was just the fact that I had some really late movement on my two-seam and my slider was really good, the cutter was decent," Keuchel said of Game 1. "So, I didn't feel the need to change speeds with the changeup, and hopefully that comes into play (Wednesday)."
Including his two playoff wins over Tanaka and the Yankees, Keuchel is 6-2 with a 1.09 ERA in eight starts versus New York, with three of those outings occurring against Tanaka.
Overall, the left-hander is 4-0 with a 1.69 ERA in five postseason appearances (four starts). Before beating the Yankees again, Keuchel allowed one run and three hits in 5 2/3 innings in Game 1 of the AL Division Series against the Boston Red Sox.
"We haven't done a whole lot off him in the starts we've seen him," Yankees manager Joe Girardi said. "Hopefully seeing him twice in one series, our guys are able to adjust a little quicker."
It will be the second postseason series Keuchel is appearing in for a second time. He started Game 3 of the 2015 ALDS against Kansas City, then three days later, he allowed three runs in the eighth inning in a relief appearance in Game 5.
The Yankees are hoping to become the fourth team to win an LCS after losing the first two games since it expanded to a best-of-seven in 1985. New York is 5-0 at home in the postseason after pulling off its biggest postseason comeback at home since Game 7 of the 2003 ALCS against the Red Sox.
Tanaka finished an inconsistent regular-season with a dynamic 15-strikeout showing against the Toronto Blue Jays on Sept. 29. He followed it up with two outstanding postseason starts.
The right-hander pitched seven dominant innings in a 1-0 victory in Game 3 of the ALDS against the Cleveland Indians before running into Keuchel again.
"I think the biggest thing is that I was able to experience the 2015 wild-card game," Tanaka said through an interpreter. "I think having that experience under my belt has helped me pitch the way I'm pitching right now."
Tanaka will be pitching Wednesday on four days' rest. Although he went 5-3 with a 4.04 ERA in eight starts on four days' rest this year, Tanaka said he believes it is not a big deal by now.
"I feel comfortable pitching four days' rest," Tanaka said. "Obviously I've done that through the season and on top of that, I've been here for four years and done that as well. So yes, I do feel comfortable."