The Grandstand’s Ricky Dimon and Joey Hanf of The Tennis Nerds preview and pick the best men’s singles matchups on Day 4 of the Australian Open. This is the fourth of 13 installments of expert picks during the season’s first Grand Slam.

Yen-Hsun Lu vs. (22) Grigor Dimitrov

Ricky: Don’t look now, but Yen-Hsun Lu is one of the hottest players on tour. Chinese Taipei’s top player boasts a 6-1 record this season and he was the best man–by a decent margin–from start to finish in Auckland (John Isner struggled all week but served his way out of trouble against Lu to win a competitive final). Lu, who destroyed countryman Jimmy Wang on Tuesday, should benefit in hot conditions against Dimitrov. The Bulgarian’s fitness has always been a question mark, as is his ability to play five-setters. Lu 6-4, 2-6, 6-7(5), 6-3, 6-2.

Joey: This one should…