Question: Who had the best singles ranking, Roberta Vinci or Jorge Lozano?

<P0-S0> Jorge Lozano (born 17 May 1963 in San Luis Potosí) is a retired professional tennis player from Mexico. <P0-S1>  He reached his highest doubles ranking of World No. 4 in August 1988. <P0-S2>  His highest singles ranking was World No. 51, achieved the following month. <P0-S3>  During his career, he won two mixed doubles titles at the French Open: in 1990 with Arantxa Sánchez, and in 1988 with Lori McNeil. <P0-S4>  He reached the round of 16 in singles at the 1988 US Open and also the semifinal in doubles that same year. <P0-S5>  Qualified twice for the Doubles Masters at the Royal Albert Hall in London and reached the semifinals in 1988. <P0-S6>  In his career, he won nine doubles titles, but no singles titles. <P0-S7>  He turned professional in 1986, and in his career, he won $U.S.739,424 in prize money. <P0-S8>  He was the first player to be beaten by Pete Sampras in the main draw of a Grand Slam tournament, at the French Open in 1989. <P0-S9>  In Davis Cup play, represented Mexico for 15 years, 1981–1995, won 12 doubles matches, and lost 12 as well. <P0-S10>  He lost 11 singles matches, and won 8, making his overall win / loss record at the Davis Cup 20–23. <P0-S11>  Lozano won his first title at Forest Hills in 1988, with his partner Todd Witsken, and won his last at Athens in 1993. <P0-S12>  He resides in Guadalajara, Mexico where he directs a tennis academy for kids and also coaches the men and women tennis team at the University Tec de Monterrey. <P0-S13>  He is currently the captain of the Mexican Davis Cup Team. <SEP> <P1-S0> Roberta Vinci (] ; born 18 February 1983) is an Italian tennis player. <P1-S1>  Up until 6 April 2015, she held the position of World No. 1 in doubles, while reaching a career-high of World No. 7 in singles in May 2016. <P1-S2>  She is the fourth Italian woman to have reached the top 10 in singles, together with Flavia Pennetta, Francesca Schiavone and Sara Errani. <P1-S3>  At 33 years and 4 days old, she is also the oldest ever player to make her first appearance in the Top 10. <SEP> <P2-S0> Flavia Pennetta (] ; born 25 February 1982) is a retired Italian professional tennis player and Grand Slam-champion in both singles and doubles. <P2-S1>  She became Italy's first top-10 female singles player on 17 August 2009 and the first Italian to be ranked world No. 1 in doubles on 28 February 2011. <P2-S2>  She became a Grand Slam singles champion, winning the 2015 US Open by defeating her childhood friend Roberta Vinci in the first all-Italian Grand Slam final . <SEP> <P3-S0> Marta Domachowska (; born 16 January 1986 in Warsaw) is a Polish retired professional tennis player ranked World No. 37 in singles (2006) and World No. 62 in doubles (2006). <P3-S1>  She reached 2008 Australian Open fourth round in singles and won 2006 Canberra International in doubles with Roberta Vinci. <P3-S2>  She also reached three WTA Tour singles finals at 2004 Hansol Korea Open (lost to Maria Sharapova), 2005 Internationaux de Strasbourg (lost to Anabel Medina Garrigues) and 2006 U.S. National Indoor Tennis Championships (lost to Sofia Arvidsson). <P3-S3>  She was 2003 Australian Open finalist in girls' singles, represented Poland at the 2008 Summer Olympics and was member of Poland Fed Cup team. <P3-S4>  Domachowska was the best female Polish tennis player after Magdalena Grzybowska's retirement and before Agnieszka Radwańska's successes.