Guillermo Garcia-Lopez fought back from a set down to defeat Taro Daniel at the Chennai Open, but Vasek Pospisil was sent crashing out in round one by last year's runner-up Aljaz Bedene.
Fifth seed Garcia-Lopez needed two hours 23 minutes to see off his Japanese opponent 4-6 7-5 6-2.
The Spaniard was unable to recover from being broken in the first game of the opener and, when the second set started in identical fashion, Daniel harboured hopes of an upset.
However, this time Garcia-Lopez hit straight back and crucially broke again in game 12 to level the match and that proved the catalyst for victory.
Pospisil did not enjoy the same fate, though, as the seventh seed was beaten 7-5 7-6 (8-6) by Bedene.
Only six places separate the two in the world rankings and that was reflected in a tight match, but ultimately it was Bedene - beaten 6-3 6-4 by Stan Wawrinka in the 2015 final - who came through.
Lukas Rosol was a 6-3 6-4 victor over Santiago Giraldo, Luca Vanni defeated Jan-Lennard Struff 6-4 7-6 (7-5) and Ramkumar Ramanathan thrashed Daniel Gimeno-Traver 6-2 6-0.
Andrey Rublev beat Somdev Devvarman 6-3 3-6 6-3, while Austin Krajicek also need three sets to see off Rajeev Ram 6-7 (0-7) 6-4 6-4.
Gilles Muller came from a set down to defeat Karen Khachanov 6-7 (3-7) 7-6 (7-4) 6-2 and Thomas Fabbiano produced a spirited turnaround to account for Jozef Kovalik in a 1-6 6-3 6-4 victory.