A late field goal of 48 yards by rookie Cairo Santos gave the Kansas City Chiefs a 23-20 win over the Chargers. The Chiefs ran 70 plays to the Chargers' 49, and controlled the ball for 39 minutes during the game to San Diego's 21. San Diego was just 3-for-10 on third down conversions after entering the game with a 53.8% success rate, the highest in the league. The loss ended the team's six-game home winning streak over the Chiefs. The Chargers got out to a 7-0 lead after tight end John Phillips' first catch of the season, a 1-yard TD from Rivers. They regained the lead, 14-10, after Gates' 27-yard TD off a tipped pass 14 seconds before halftime. San Diego was limited to just one offensive drive in the third quarter, a three-and-out series that lasted just 1:02, and Kansas City led 20-14 after an Alex Smith 11-yard TD pass to Anthony Sherman with 14:50 left in the fourth. The Chargers responded with a 12-play drive, driving all the way to the Chiefs 6, but settled for a Novak 24-yard field goal. After a defensive stop, Novak kicked a 48-yarder to tied the game at 20 with 1:57 remaining. It was his 31st straight field goal, breaking Carney's team record of 29 set from 1992 to 1993. However, the Chiefs drove 62 yards on nine plays on their game-winning drive. Rivers was 17 of 31 for 205 yards and two touchdowns with a 83.4 rating, breaking his streak of games with 120 or higher. The Chargers' offense had season lows of 205 passing yards and 251 total yards. Smith, the first established quarterback the Chargers had faced in four games, was 19 of 28 passes for 221 yards. Chiefs coach Andy Reid, in his second year with the team, improved his career record to 14-2 coming off a bye week. Retired defensive end Leslie O'Neal was inducted into the Chargers Hall of Fame at halftime. This was the first of two games in which the Chargers wore their alternate powder blue jerseys &#8212; the other was against the New England Patriots on December 7.
Question: Who threw the first touchdown pass of the game?
Answer: Rivers