Former world number one Andy Murray knocked out fifth seed Hubert Harkaz 6-4, 6-7 (6/8), 6-3 in the opening round in Vienna on Monday.
Murray had lost twice to Wimbledon semi-finalists Harkaz this year but broke his losing run against Pool despite losing a match point in the second set tiebreak.
The three-time Grand Slam champion, whose ranking has dropped to 156 after a series of injuries, will meet young Spanish star Carlos Alcaraz in the second round of the tournament, which he won in 2014 and 2016.
“It was a good match that could have gone anyway,” Murray said.
“I was disappointed to leave the service in the opening game of the third, but thankfully I was able to take the break back in the next game and from there I probably deserved to cross the line. It was a good win in difficult situations.”
Harkaz’s defeat dealt a major blow to his hopes of reaching the final ATP Finals of the season. He is currently in the last round of qualifying but could be overtaken by this week’s Antwerp champion Jank Sunner.