Carlos Alcaraz continues to break new ground in what has been a breakthrough ATP campaign for the Spanish teenager.On Saturday, the 19-year-old prevailed over Giulio Zeppieri to reach back-to-back Umag finals, setting up a blockbuster title clash with Jannik Sinner. The win meant Alcaraz will now break into the top four of the ATP singles on Monday.The teenager could have achieved that six days ago had he beaten Lorenzo Musetti in the Hamburg final last Sunday. However, just a week later, the World No. 5 is now poised to enter the top four as he eyes a tour-leading fifth title of the year.ATP Tour@atptour.@carlosalcaraz has his on the prize @CroatiaOpenUmag | #CroatiaOpenUmag16513.@carlosalcaraz has his 👀 on the prize 🏆@CroatiaOpenUmag | #CroatiaOpenUmag https://t.co/ubyDnSD1vUAlcaraz is one of the youngest players to reach the top four of the ATP rankings. On that note, here's a look at the six youngest singles players to reach the ATP top four since the rankings came into being almost five decades ago:#6 Carlos Alcaraz (2022) - 19 years, 2 monthsCarlos Alcaraz will be a top-four player on MondayCarlos Alcaraz has been on a roll this year, winning 42 of his 48 singles matches and bagging four titles. That includes triumphs in Miami and Madrid, making the Spaniard the youngest two-time Masters 1000 champion in nearly two decades.His win over Zeppieri in Umag on Saturday confirmed his debut in the ATP top four next week. Alcaraz (75-24) will now look to mark the occasion - his 100th singles match - with a victory as he seeks the first successful title defense of his young career.ATP Tour@atptourGrab your 🍿 This is a matchup you won't want to miss!@carlosalcaraz @janniksin @CroatiaOpenUmag | #CroatiaOpenUmag18824Grab your 🍿 This is a matchup you won't want to miss!@carlosalcaraz 🆚 @janniksin @CroatiaOpenUmag | #CroatiaOpenUmag https://t.co/5SiK98yDn1It was at Umag last year that the then 18-year-old won the first of his five ATP singles titles. A year later, he'll vie to win his sixth against Jannik Sinner.#5 Mats Wilander (1983) - 19 years, 1 monthMats Wilander at the 1983 French OpenMats Wilander became the youngest male player in the Open Era to win a Grand Slam singles title when he triumphed at 1982 Roland Garros on his tournament debut.A year later, he lost to Yannick Noah in the final, but enjoyed what was one of the best years by a teenager in ATP history. The Swede went 83-11 on the year, winning nine titles, including the Australian Open.ITF Media@ITFMediaIn 1983, Yannick Noah won the @rolandgarros men's singles title, defeating Mats Wilander in the final to become the first French champion since Marcel Bernard in 1946.Noah remains the only Frenchman to have won a Grand Slam singles title in the Open Era.7423In 1983, Yannick Noah won the @rolandgarros men's singles title, defeating Mats Wilander in the final to become the first French champion since Marcel Bernard in 1946.Noah remains the only Frenchman to have won a Grand Slam singles title in the Open Era. https://t.co/lLbfPlXfiPA week after winning his seventh title of the year in Barcelona, Wilander broke into the top four of the rankings. The future World No. 1 would end the year in the top four, with two more titles - Stockholm and the Australian Open - becoming the youngest winner Down Under.#4 Rafael Nadal (2005) - 19 years, 3 daysRafael Nadal broke into the ATP top four in 2005Rafael Nadal is widely regarded as one of the finest players to have graced the sport.The 22-time Major winner announced his arrival on the big stage in 2005. The then 19-year-old went 79-10 on the year, producing the best season by a teenager in ATP history, winning 11 titles.At Roland Garros that year, the legendary left-hander beat Mariano Puerta in the final to become the first debutant since Wilander to win the claycourt Major. Following the triumph, Nadal broke into the top three of the ATP rankings.TENNIS@Tennis2005 202217 years ago to the day...And still just as special.#RolandGarros | @RafaelNadal816411882005 ➡️ 202217 years ago to the day...And still just as special.#RolandGarros | @RafaelNadal https://t.co/bCD0Ecg0r0Suffice to say, it wasn't going to be his only Roland Garros success. Earlier this year, the 36-year-old won a record-extending 14th title on the Parisian terre battue.#3 Boris Becker (1986) - 18 years, 4 monthsBoris Becker successfully defended his Wimbledon title in 1986Boris Becker announced his arrival on the big stage when the then 17-year-old romped to the Wimbledon title in 1985.A year later, the German teenager showed he was no flash in the pan, enjoying a 69-13 year, winning six titles. That included a successful title defense at Wimbledon - where he beat Ivan Lendl in the final.Classic Boris Becker@beckerclassicsWimbledon 1986.... BB gets wins over Pernfors 4th rd, Mecir QF, Leconte SF and Lendl in the final 64 63 75215Wimbledon 1986.... BB gets wins over Pernfors 4th rd, Mecir QF, Leconte SF and Lendl in the final 64 63 75 https://t.co/bAFCMMxGNDBecker won his first title of the year in Chicago. Weeks later, he lost to Anders Jarryd in the final of the WCT Finals in Dallas. Nevertheless, he broke into the top four of the ATP rankings, becoming only the third 18-year-old to do so.#2 Bjorn Borg (1974) - 18 years, 3 months, 24 daysBjorn Borg had a banner year in 1974Bjorn Borg is widely regarded as one of the best players in tennis history. The Swede enjoyed a banner year in 1974. The then 18-year-old won nearly 100 matches that year, going 94-24, winning eight titles. That included his first of six Roland Garros titles.A few days after winning his sixth title of the year in Bastad, Borg broke into the top four of the ATP rankings. He lost in the Madrid final to Ilie Nastase but ended the year with one more title - Adelaide.Laver Cup@LaverCupOn this day in 1974 #TeamEurope captain Bjorn Borg won the first Grand Slam singles title of his career @rolandgarros. He was 17.23953On this day in 1974 #TeamEurope captain Bjorn Borg won the first Grand Slam singles title of his career @rolandgarros. He was 17. https://t.co/uOXd8KSwJZThe future World No. 1 would go on to win the Roland Garros-Wimbledon double in three successive years (1978-80), which remains an unmatched feat.#1 Andre Agassi (1988) - 18 years, 3 months, 2 daysAndre Agassi at the 1988 US OpenAndre Agassi is one of only five male players in the Open Era to have won the career Grand Slam.A year after winning his first of 60 ATP singles titles at Itaparica (Brazil) in 1987, the then 18-year-old American would enjoy a memorable campaign. Agassi went 63-11 in 1988, winning six titles.After winning his fifth title of the year at Stratton Mountain, the American became the youngest player to break into the top four of the singles rankings.MisterOnly.Tennis@OnlyRogerCanFly Tenistas más jóvenes en el Top4 del ATP Ranking (1973-2022/Men’s Singles): Andre Agassi | 18y 3m 2d, 1988 Bjorn Borg | 18y 3m 24d, 1974 Boris Becker | 18y 4m, 1986 Rafa Nadal | 19y 3d, 2005 Mats Wilander | 19y 1m, 1983 Carlos Alcaraz | 19y 2m, 202226950📊 Tenistas más jóvenes en el Top4 del ATP Ranking (1973-2022/Men’s Singles):🇺🇸 Andre Agassi | 18y 3m 2d, 1988🇸🇪 Bjorn Borg | 18y 3m 24d, 1974🇩🇪 Boris Becker | 18y 4m, 1986🇪🇸 Rafa Nadal | 19y 3d, 2005🇸🇪 Mats Wilander | 19y 1m, 1983🇪🇸 Carlos Alcaraz | 19y 2m, 2022 https://t.co/4y7pFAlFKlAlthough Agassi didn't win a Major that year - reaching the semifinals at Roland Garros and the US Open - he ended the season with a triumph at Livingston.