East Zone turned in a disciplined all-round performance to beat West by five wickets and make it to the semi-finals of the Duleep Trophy, in Valsad, on Monday.
East will meet North in the semi-final, scheduled to be played in Delhi from February 4.
After a batting collapse that saw West lose five wickets for 21 runs, East were left to chase a target of 173, which they successfully did in 56.3 overs despite a few hiccups.
Having conceded the first innings lead, West, who were leading by 102 runs at the end of the third day, needed to put up a decent total in order to enforce an outright victory.
Kaustubh Pawar (37, 80 balls, 6x4) and Abhishek Nayar (58, 59 balls, 4x4, 3x6) started in right earnest, the latter attacking the East bowlers. Their sixth-wicket partnership produced 69 runs.
But at 180 for five, Ashok Dinda started the slide, when he forced Kaustubh to edge one to Shreevats Goswami behind the stumps.
Dinda then bowled Akshay Darekar (1) in his next over.
Starting to run out of partners, Nayar began a counter-attack, hitting a couple of sixes off left-arm spinner Shahbaz Nadeem, to complete his 50 and the team's 200.
But Nadeem got both Sandeep Maniar (1) and Samad Fallah (0) before Dinda dismissed Nayar caught by Behera.
When East commenced their chase, almost all batsmen got good starts but couldn't finish off the game as they were reduced to 121 for five. Left-arm spinner Darekar (5-87) got all the wickets.
But an unbroken 52-run stand between Biplab Samantray (27 not out) and Anushtup Majumdar (26 not out) clinched the issue.
Nataraj Behera contributed 34.
Brief Scores: West Zone 314 & 201 (A Nayar 58, A Dinda 3-82, A N Ahmed 3-31). East Zone 343 & 173-5 (Nataraj Behera 34, A Majumdar 27 not out).