Question: Which German Formula One racing driver shared the lead in the with Lewis Hamilton in the lead in 2017 Formula One Driver's Championship?

Context paragraphs:
2017 Bahrain Grand Prix: The 2017 Bahrain Grand Prix (formally known as the 2017 Formula 1 Gulf Air Bahrain Grand Prix) was a Formula One motor race that took place on 16 April 2017 at the Bahrain International Circuit in Sakhir, Bahrain.  The race was the third round of the 2017 season and marked the thirteenth time that the Bahrain Grand Prix has been run as a round of the Formula One World Championship.  The winner of the previous Bahrain Grand Prix, Nico Rosberg, did not compete as he had retired after the 2016 season.  Before the race, Sebastian Vettel and Lewis Hamilton shared the lead in the Drivers' Championship.  Mercedes led the Constructors' Championship by one point over Ferrari.

Max Verstappen: Max Emilian Verstappen (] ; born 30 September 1997) is a Belgian-Dutch racing driver who competes under the Dutch flag in Formula One with Red Bull Racing.  Aged , he became the youngest driver to compete in Formula 1 at the 2015 Australian Grand Prix for Scuderia Toro Rosso.  He is also the youngest driver to lead a lap during a Formula One Grand Prix, youngest driver to set the fastest lap during a Formula One Grand Prix, youngest driver to score points, youngest driver to secure a podium and youngest Formula One Grand Prix winner in history.

Lewis Hamilton: Lewis Carl Davidson Hamilton, MBE, (born 7 January 1985) is a British racing driver who races in Formula One for the Mercedes AMG Petronas team.  A three-time Formula One World Champion, he is often considered the best driver of his generation and widely regarded as one of the greatest Formula One drivers in the history of the sport.  He won his first World Championship title with McLaren in 2008 before moving to Mercedes, where he won back-to-back titles in 2014 and 2015.  Hamilton has more race victories than any other British driver in the history of Formula One ( ), and holds records for the all-time most career points ( ), the most wins at different circuits (24), the all-time most pole positions ( ), as well as achieving the joint-most podium finishes in a season (17).  Hamilton is also the only driver to have won at least one Grand Prix in every season he has competed in.

McLaren MP4-27: The McLaren MP4-27 was a Formula One racing car designed by Vodafone McLaren Mercedes for the 2012 Formula One season.  The car was driven by former World Champions Jenson Button and Lewis Hamilton.  It was launched on 1 February at the McLaren team base in Woking, Surrey, ahead of the first winter test sessions at Jerez de la Frontera.  This was the last McLaren car that Lewis Hamilton drove for the team, as he moved to the Mercedes AMG Petronas F1 Team in 2013.  s of May 2017 , it is also the last car made by McLaren to achieve a race victory.

2009 Singapore Grand Prix: The 2009 Singapore Grand Prix (formally the 2009 Formula 1 SingTel Singapore Grand Prix) was a Formula One motor race held at the Marina Bay Street Circuit in Singapore on 27 September 2009.  The 61-lap race was the fourteenth round of the 2009 Formula One season.  It was the second Singapore Grand Prix to be part of a Formula One Championship and the tenth Singapore Grand Prix overall.  It was also the second Formula One race to be held at night.  The race was won by McLaren-Mercedes driver and reigning World Champion Lewis Hamilton.  Toyota's Timo Glock finished second and 2008 race winner Fernando Alonso took third position, making this the only race of the season with neither a Brawn nor a Red Bull driver on the podium.  This was also the last race of 2009 for Glock, as he was injured during qualifying for the Japanese Grand Prix and was replaced by test driver Kamui Kobayashi.  Heikki Kovalainen scored his last ever World Championship points at this race.

Sebastian Vettel: Sebastian Vettel (] ; born 3 July 1987) is a German racing driver currently driving in Formula One for Scuderia Ferrari.  He is a four-time Formula One World Champion, having won the championship in , , and with Red Bull Racing, therefore being among the most successful F1 drivers of all time, as he is one of only four drivers to have won four or more drivers' titles.  He is regarded by fellow and former drivers as one of the greatest Formula One drivers in the history of the sport.  Vettel signed a three-year contract with Ferrari upon his arrival, a contract later extended until the end of 2020.

2014 Bahrain Grand Prix: The 2014 Bahrain Grand Prix (formally the 2014 Formula 1 Gulf Air Bahrain Grand Prix) was a Formula One motor race held on 6 April at the Bahrain International Circuit in Sakhir, Bahrain.  It was the third round of the 2014 Formula One season, the 900th Formula One World Championship event, and the eleventh running of the race.  The 57-lap race was won by Mercedes driver Lewis Hamilton who started from second position.  His teammate Nico Rosberg finished second and Force India driver Sergio Pérez came in third.  It was Hamilton's second victory of the season, his first in Bahrain, and the 24th of his Formula One career.

2014 Monaco Grand Prix: The 2014 Monaco Grand Prix (formally the Formula 1 Grand Prix de Monaco 2014) was a Formula One motor race held on 25 May at the Circuit de Monaco in Monte Carlo.  It was the sixth race of the 2014 Formula One season and the 61st running of the event as part of the Formula One World Championship.  The 78-lap race was won by Mercedes driver Nico Rosberg after starting from pole position.  His teammate Lewis Hamilton finished second and Red Bull Racing driver Daniel Ricciardo came in third.  It was Rosberg's second victory of the season, his second consecutive win at Monaco, and the fifth of his career.

2014 Japanese Grand Prix: The 2014 Japanese Grand Prix (formally the 2014 Formula 1 Japanese Grand Prix) was a Formula One motor race held on 5 October at the Suzuka Circuit in Suzuka, Mie.  It was the fifteenth round of the 2014 Formula One season and the 30th Japanese Grand Prix held as part of the Formula One World Championship.  The 44-lap race was won by Mercedes driver Lewis Hamilton, who started from second position.  His teammate, Nico Rosberg, finished second and Red Bull Racing driver Sebastian Vettel came in third.  It was Hamilton's eighth victory of the season, his first at Suzuka and the 30th of his Formula One career.

McLaren MP4-26: The McLaren MP4-26 was a Formula One racing car designed by McLaren for the 2011 Formula One season.  It was driven by Lewis Hamilton and Jenson Button, the and World Drivers' Champions, respectively.  The car was launched on 4 February at Potsdamer Platz located in Berlin, Germany, shortly after the first test session of the season in Valencia.  McLaren test driver Gary Paffett, Lewis Hamilton and Jenson Button drove an interim version of the car's predecessor, the MP4-25 at the first tests to get experience with the final tyre compounds provided by new tyre supplier Pirelli.  Right before the 2011 Singapore Grand Prix, McLaren signed a new sponsor: Lucozade and the logo replaced the Johnnie Walker logo on the sides of the rear wing, thus shifting the Johnnie Walker logo to the back of the rear wing, which changed from red to silver in colour.

Supporting paragraphs: 2017 Bahrain Grand Prix Sebastian Vettel
Answer: Sebastian Vettel