Guido Pella

As a junior Pella posted a 19–5 record in singles and reached as high as No. 42 in the combined world rankings in 2008.[8] Entering as a qualifier, he reached the semifinals of the French Open boys' singles in 2008, upsetting first-seeded Bernard Tomic in the quarterfinals (and losing to Jerzy Janowicz).

Pella started playing Futures tournaments in 2005, winning his first at Peru F3 in July 2008 without dropping a set. In the following years, he won six further Futures titles, all of them on clay. His first Challenger final came at Guayaquil, Ecuador in November 2011, losing the match to Matteo Viola in straight sets. He finished the 2011 season ranked world no. 350 in singles and no. 501 in doubles.

Pella started his 2012 Challenger season in March, capturing his first title in that category at the Salinas Challenger in Ecuador, with a victory over Paolo Lorenzi in the final round. The following month, he won his first doubles Challenger title at the Pereira Challenger in Colombia, partnering Martín Alund.

In May, he entered the French Open qualifying draw, losing in the first round to former world no. 2 Tommy Haas.[9] In August, he won his first hard-court tournament at the Manta Challenger, beating Maximiliano Estévez in the final. In the US Open, he made it through the qualifying stage of the tournament, beating Lukáš Rosol to reach his first Grand Slam main-draw match, which he lost to Nikolay Davydenko in four sets.[10] In September, he defeated Alex Bogomolov, Jr. and Leonardo Kirche on his way to win the Campinas Challenger in Brazil.

He cracked the top 100 for the first time after winning the 2012 ATP Challenger Tour Finals, defeating Adrian Ungur in the final round.[11] Pella finished the year ranked world no. 97 in singles and world no. 187 in doubles,[12] a career high and a 249-spots improvement since the beginning of the season.

Guido Pella entered the 2013 Australian Open main draw directly, but he lost in the first round to qualifier Amir Weintraub. He then competed in Viña del Mar, also losing in the first round, this time to countryman Federico Delbonis. The following week, he played at the Brasil Open, winning his first ATP World Tour-level match against sixth seed Fabio Fognini,[13] losing then in the second round to eventual finalist David Nalbandian. At 2013 Düsseldorf, he advanced to his first ATP SF starting as a qualifier, defeating No. 10 Janko Tipsarević along the way.

Pella reached his fourth ATP Tour final in Córdoba Open in February, but lost to compatriot Juan Ignacio Londero in three sets. Having lost each of his previous four finals, in March 2019, he won his first ATP title in 2019 Brasil Open. He defeated Christian Garin in straight sets.[14] At Wimbledon in July, he reached his first-ever Grand Slam singles quarterfinal by defeating former World Number 3 and 2016 Wimbledon finalist Milos Raonic in five sets from two sets down.[15] The victory marked his third against the most-recent runners-up of Wimbledon: He had previously defeated 2017 Wimbledon finalist Marin Čilić in the second round of 2018 Wimbledon, also from two sets down, and 2018 Wimbledon finalist Kevin Anderson in the third round of the 2019 championships.