Ward's tally broke a 2-2 tie and added an assist for the Capitals, who extended their season-high winning streak to four games and jumped two points ahead of idle Winnipeg for first place in the Southeast Division.
Capitals goalie Michal Neuvirth made 28 saves, while Ben Bishop game up three goals on 37 shots.
Vincent Lecavalier provided a goal and an assist and Alex Killorn also scored for the Lightning.
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