21:31 CET - Things could hardly be going better for Zverev, who won the opening set 6-3 in just 28 minutes. Shelton has held his serve at the start of the second, but he needs to step things up now.
20:45 CET - The second match of the opening day is underway in Turin, with Ben Shelton making his ATP Finals debut against former champion Alexander Zverev.
Follow every point of the match here.
19:39 CET - Let's check back in with the doubles tournament going on in Turin, where the Italian pairing of Simone Bolleli and Andrea Vavassori have overcome Julian Cash and Lloyd Glasspool in straight sets 7-5, 6-3.
15:52 CET - Carlos Alcaraz showed his class in the second set against Alex De Minaur to secure an opening win at the ATP Finals, defeating the Australian 7-6(5), 6-2 to move top of the Jimmy Connors Group. The Spaniard had 20 winners in the contest compared to seven for his opponent, but he will want to cut out the unforced errors this week in Turin.
15:17 CET - Well, if the ATP Finals continue like the first set between Carlos Alcaraz and Alex De Minaur, then we are in for a cracking week. The Australian fought back to force a tie break against Alcaraz, but the Spaniard persevered to win the first set 7-6(5).
13:16 CET - With just two singles games across the schedule today, let's get you up to speed with the other tournament going on in Turin.
In the opening doubles game of the Finals, Marcel Granollers and Horacio Zeballos have won in a tight affair against Kevin Krawietz and Tim Puetz 6-4, 4-6, 10-6.
12:00 CET - Hello and welcome to our coverage of today's tennis as the prestigious ATP Finals get underway in Turin!
The first match of the tournament sees six-time major champion Carlos Alcaraz take on world number seven Alex de Minaur in the Jimmy Connors Group at 14:00 CET.
The pair have met four times before, with the Spaniard ominously winning all four meetings.
Later on, the second game of the day sees Ben Shelton come up against Alexander Zverev in the Bjorn Borg Group at 20:30 CET.
The experienced German boasts a dominant 4-0 head-to-head record over the American, making him the clear favourite heading into the match.
