The Oakland Athletics became the first team to clinch a division title this season when they wrapped up the American League West on Monday night. The A's secured the West on a scheduled off day with some help from the Seattle Mariners, who edged the Houston Astros. The loss put the Astros 6.5 games behind the Athletics with six to play.

This is Oakland's first division championship since 2013. In the six seasons between then and this year, the A's had finished second and fifth three times apiece. That included a second-place finish last year, which saw the A's subsequently lose to the Tampa Bay Rays in the Wild Card Game.

The A's received some bad news the weekend before last, as star third baseman Matt Chapman was announced as being out for the remainder of the season. Nonetheless, Oakland has received stellar production from free-agent pickup Jake Lamb, who entered the week hitting .364/.417/.727 in his first six games. 

Conversely, this is the first time the Astros have failed to win the West since 2016. They had won three consecutive division crowns, and had advanced to at least the American League Championship Series in each of those years. The Astros are still expected to make the playoffs. The Astros' first-round opponent would currently be the Athletics.

While the A's are the first team to secure their division, they're not the only team to have already punched its ticket to the postseason. The Tampa Bay Rays, Chicago White Sox, Minnesota Twins, and New York Yankees have done so as well from the AL, while the Los Angeles Dodgers and San Diego Padres have clinched in the National League.