The Islanders moved within one point of the Washington Capitals for the second wildcard spot in the Eastern Conference.
Horvat scored a power-play goal 93 seconds into the third to tie the game. The Islanders had failed to convert their previous 15 power plays. Holmstrom snapped the tie with 11:35 remaining in the game after a miscue by Chicago goalie Petr Mrazek. Mrazek made 27 saves, including 24 in the opening two periods.
Jason Dickinson scored in the first for the Blackhawks, whose 4-3 overtime win over the Islanders on January 19 in Chicago led to New York firing coach Lane Lambert and replacing him with Patrick Roy. New York goalie Ilya Sorokin made 18 saves Tuesday to stop a six-game losing streak.
Golden Knights 6, Canucks 3
Jonathan Marchessault had a goal and two assists and Jack Eichel and Anthony Mantha each added a goal and an assist as hosts Vegas beat Vancouver for a third straight win.
William Karlsson, Noah Hanifin and Brett Howden also scored goals and Ivan Barbashev added two assists for the Golden Knights, who improved their third-place lead in the Pacific Division to five points over Los Angeles. Logan Thompson finished with 27 saves to win his sixth consecutive start.
Quinn Hughes scored two goals and Nils Hoglander also scored for Pacific Division leaders Vancouver, who lost for the third time in their last four games. Casey DeSmith made 24 saves for the Canucks, who were playing their first road game since March 7.
Bruins 3, Predators 0
Linus Ullmark made 31 saves for his second shutout of the season, and Boston scored three goals in the final seven minutes of the third period en route to a shutout win over hosts Nashville.
The game was scoreless until Charlie Coyle scored a short-handed goal with 6:42 left, lifting Boston to their second consecutive win. David Pastrnak and Pavel Zacha rounded out Boston's scoring with a goal and an assist each. Danton Heinen also dished out two assists and Ullmark picked up one assist on Coyle's goal.
Nashville have now lost three straight since an 18-game points streak that is the longest in the NHL this season. Juuse Saros stopped 29 shots in the Predators' net.
Penguins 6, Devils 3
Pittsburgh scored five unanswered goals to erase a third-period deficit and beat hosts New Jersey in Newark and add space between the teams in the playoff race.
Evgeni Malkin scored twice and added an assist and Sidney Crosby added a pair of goals for the Penguins, who avoided being swept in the three-game season series with New Jersey.
With the win, Pittsburgh created a three-point cushion over the Devils in the Eastern Conference wild-card race. The Penguins still sit three points behind Washington for that second wild-card spot.
Wild 3, Senators 2
Vinni Lettieri scored the go-ahead goal with 6:56 remaining in the third period, lifting Minnesota past Ottawa in Saint Paul, Minn.
Fellow fourth-liner Mason Shaw scored his first goal since sustaining his fourth career ACL injury last season, and Matt Boldy also tallied. Marc-Andre Fleury made 30 saves for the Wild, who improved to 8-1-4 in their last 13 games.
Ottawa's Drake Batherson and defenseman Jakob Chychrun each scored and set up the other's power-play goal for the Senators, who saw their five-game winning streak come to a halt.
