Marcus Johansson scored his second goal of the game at 6:31 of overtime as the Washington Capitals defeated Toronto 2-1 Sunday to win their first round playoff series four games to two. The 26-year-old Swedish forward also scored in the third period to tie the game and force overtime in the best-of-seven National Hockey League playoff series. The Capitals will face Sidney Crosby's Pittsburgh Penguins in the second round. On the game-winner, Johansson knocked in the puck after Justin Williams got it to the front of the net. It was the fifth game of the series to be decided in overtime and all six were decided by one goal. American rookie Auston Matthews scored for Toronto early in the third period. The game turned into a battle of goaltenders as Washington's Braden Holtby made 37 saves and Toronto's Frederik Andersen finished with 34 stops. In Boston, Clarke MacArthur scored a power-play goal 6:30 into overtime to give Ottawa a 3-2 victory that advanced the Senators into the second round. Ottawa won the first-round Eastern Conference playoff series 4-2 and booked a second-round showdown against the New York Rangers, who ousted Montreal in round one. MacArthur only returned to the Senators on April 4 after an 18-month absence following a concussion suffered in October 2015 against Columbus. The 32-year-old left wing missed 156 games and played only four regular season games this month but netted two precious goals in six playoff contests against Boston, the biggest the series winner. The Senators won three games of the series in overtime on the way to capturing only their second playoff series triumph in a decade. Boston's Drew Stafford opened the scoring with a power-play goal just 1:47 before the end of the first period. But Ottawa answered in the second period, Bobby Ryan tipping in the equalizer on the power play just 3:26 into the period and Kyle Turris netting his first goal of the series just 5:06 later to give the Senators the lead. The Bruins answered 1:57 into the third period on Patrice Bergeron's wrist shot, pulling Boston level at 2-2. The Capitals had the NHL's best record this season while the Maple Leafs only reached the playoffs in the final weekend of the campaign. Oilers-Ducks open second round Wednesday The NHL postseason is down to eight teams with the St. Louis Blues hosting the Nashville Predators and the Anaheim Ducks hosting the Edmonton Oilers to start the second round of the Stanley Cup playoffs Wednesday night. After the two Western Conference series get going, the Ottawa Senators host the New York Rangers and the Washington Capitals host the defending Stanley Cup champion Pittsburgh Penguins on Thursday night. Washington versus Pittsburgh is a showdown of the top two teams in the league during the regular season. The Atlantic Division champion Montreal Canadiens and Central champion Chicago Blackhawks were eliminated in a first round that set a record for the most overtime games with 18. It was the first time a first round didn't feature a Game 7 in any series since 2001. — Agencies