Chardy won their only previous meeting. That was in September 2015 in Kuala Lumpur. He won in 3 sets on an indoor court.
Zverev lost to Darcis in a Davis Cup tie at the weekend. He needed 3 sets to

beat Bedene yesterday. He can often lift his game against the top players but can be less focused against players he is expected to beat.
Chardy has played 3 sets in both his matches this week. He has faced 17 break points in the 2 matches but was broken just 3 times in 6 sets.
Zverev is not at his best and we could again see 3 sets or at least a tie break.
Back Zverev if he is broken first. He starts around 1.43.